BOULDER - The Conrad Obi false alarms have been sounded before. Take Fall Camp 2010 . . . a massive interior lineman whose playing time and productivity had never quite matched his size, Obi made noise in August but wasn't heard from much thereafter along Colorado's defensive front.

Fast forward to Spring Practice 2011 . . . and once more here's Obi shedding blocks, filling gaps, raising eyebrows and turning heads.

Yet another false alarm?

The amiable, intensely focused Obi doesn't think so, and Mike Tuiasosopo - CU's new defensive line coach - desperately wants to believe there's nothing counterfeit about what he's seeing from the fifth-year senior.

Said "Tui:" "From what I hear from everybody around me, this is the best they've ever seen him play. Now, of course, I'm always looking for more. I'm trying to get him better every day. But the guy's attitude is unbelievable. When we first got here, we told all of them, 'It's a clean slate. You have to earn your way.' To me, that dude is earning his way."

Obi believes his upgraded performance has a simple explanation: "It's hard work paying off. I'm doing what I want to do and seeing the results I wanted to see, that's what makes it the best spring I've had here."

Lured last winter from Arizona when new CU Coach Jon Embree was assembling his staff, Tuiasosopo went into spring drills with no preconceived notions about any of the Buffs' down linemen. If he had, he might have focused on the development of returning starters Curtis Cunningham (senior nosetackle) and Will Pericak (junior tackle) and given Obi, who has averaged only a handful of plays a game during his career, little more than a casual glance.

"I'd never seen this dude," Tuiasosopo said of Obi. "But it's one of those things where it's on tape (Obi's spring productivity). I mean, we had a guy who was an all-conference player (Pericak was an honorable mention All-Big 12 coaches selection last season) here that got displaced because of the way he's playing. Then Curtis gets hurt. But it's all on tape. We ain't playing any games; the best players play.

"We've got a big sign in our meeting room - Playmakers Make Plays Because They Play Hard. Now, there's some technical things he can work on and I have to coach him up there. But man, I'll tell you what, he's making a lot of plays because he's playing hard. And I take my hat off to that."

With Cunningham out, Obi is playing mostly nose tackle but occasionally moves to the other tackle spot. Those two positions comprise what Tuiasosopo calls "the heart" of our defense, "and I'm counting on (Obi) to be the heart."

That's a sizeable responsibility for a guy who logged only 14 games in high school (he missed most of his senior season with a hand injury) and initially played defensive end at CU before shifting inside two seasons ago.

There were two reasons Obi stayed at defensive end for a couple of seasons: He had it in his head that he belonged there, and his body type fit the position. Two years and 50 pounds later, head and body messaged him and his coaches that a move inside with a hand on the ground was his natural spot. He now believes it.

"I wouldn't say it was a rough transition because I had wanted to play D-end," he said. "Now, I feel like (moving inside) was a blessing in disguise. I just have to work with what I've got."

And that's considerable. Standing 6-foot-3, he's now a lean 290 pounds and in his best shape since leaving Grayson, Ga., for Boulder as a 240-pound end. "This is a great weight for me; I'm moving better than I ever have," he said.

And the guys he goes against in the offensive line have noticed. Senior right guard Ryan Miller said Obi's ramped up work ethic has had obvious results: "He's always one of the last guys off the field, and he's gotten a heck of a lot stronger. He's put a lot more work into it than other guys have and it's starting to pay off. It's really starting to show."

Plus, noted Miller, Obi is "much more focused in practice, much more focused in everything he does. Every aspect of the game he seems more tuned in. I know he's making things harder for me."

Obi called his junior season frustrating, but is reluctant to say he's approached this spring really for what it is - a final opportunity to put himself on the field more this fall.

"That's a factor," he admitted, "but the biggest factor to me was just going out there and doing what I do. You have to have a plan; you do your job and make plays along the way. That's what I have my head focused on. I'm glad I can get those things done."

Then there was the coaching change. While it undoubtedly has resulted in a team-wide attitude adjustment, in some cases it has been a convenient way to write off inconsistent, sub-par individual performances under the former regime. Obi might fit into that category, but whatever has touched match to fuse, well, Tuisasosopo is interested only in the bang.

"Yeah, he's doing it, he's meeting my standard," Tuiasosopo said. "I'm very happy with his progress, but I always expect my guys to keep climbing the ladder. The thing about a guy like Conrad - and all these guys, really - is that we're all trying to get to know each other. But at the end of the day we're judging everybody on production. And that guy has been productive."

The overall spring productivity in Tuiasosopo's group, though, has been hampered by injuries, particularly at end. At least four of those players have missed portions of the 15 practices. Pericak has stayed relatively healthy, but Cunningham's elbow injury likely will keep him out of Saturday's Spring Game (6 p.m., Folsom Field). Still, Tuiasosopo said before the injury Cunningham had shown that "he plays hard and understands the game . . . but there are some technical, fundamental things he has to work at."

Tuiasosopo's interior numbers for fall camp are fixed. In February, CU signed a pair of prospective outside linebackers/defensive ends, but no down linemen. Nosetackle Eugene Goree, a senior-to-be, left the program. Junior Eric Richter has moved from the O-line to the D-line, and Tuiasosopo is still waiting for that switch to pay dividends: "He needs to bring something to the table." Sophomore Nate Bonsu, who missed last spring's work after undergoing off-season knee surgery, is trying to regain the form that saw him play in 12 games as a true freshman.

All of which makes it critical for Obi to make his spring reemergence last, carrying it through the summer and into fall. Not only would that benefit the Buffs, it would at least offer Obi a chance to carve out an NFL opportunity.

"That's my goal and my dream, and I'm going to do everything in my power to get there," he said. "I know it's going to take more steps along the way, but I'm willing to take them."

DAY OF RECKONING AWAITS: Embree says "95 percent" of the players he inherited have done what's required of them to be on the team when the 2011 season starts. As for the other 5 percent, sometime after the conclusion of spring drills, there will be exit interviews - conducted by Embree.

His criteria for remaining on the team:

"If they can't play and they're not doing what they're supposed to do academically and not doing some other things and buying into the program, they won't be here. It's just that simple.

"I told them when I was hired everybody has a clean slate. This will be four months to show me if you want to be a part of this. I told them it's a privilege to be a Buffalo - it's not a right. So they've had since Dec. 7 to show they want to be here. Some guys don't want to be here - by their body language, by how they work in the weight room, by how they work in the classroom, by how they work on the football field."

Embree said all returning players were "warned many times. There are no surprises. I've told them from Day 1, everyone is year-to-year. It's simple; I don't ask a lot. I want effort, I want you to compete. I want you to do it on and off the field. That's all I ask. Be on time. I think those are pretty simple rules. But for some guys, they can't do that."

BUFF BITS: With the exception of "a couple of defensive lapses," Friday's final practice before the Spring Game went well, Embree said. "It was a good practice . . . guys are showing who they are. That's what we wanted out here in the evaluation process." . . . . Aside from sophomore Paul Richardson and senior Toney Clemons (when he was healthy), the receiving corps remains short on playmakers. "After that no one really stepped up and said I'm the next one in line," Embree noted. Of Richardson, he said, "He's fast, good with the ball after he catches it. He has very good hands . . . he's almost at the point where literally anything near him he'll catch. He's a football player, he understands. And he's hard on himself; he wants to be better." . . . . Embree said senior quarterback Tyler Hansen has developed good chemistry with Richardson, Clemons and senior tight end Ryan Deehan . . . . Former CU Coach Gary Barnett is coaching in Saturday's alumni flag football game opposite ex-coach Bill McCartney because "he's a Buff - that's why I wanted him back," Embree said. "He's an integral part of this program. I remember first meeting him in '84 as an assistant coach. I admired his intensity . . . we're a family and he's a big part of that family. So I think he needs to be here, to be around." The alumni flag football game starts at 4:30 p.m.

Contact: BG.Brooks@Colorado.EDU