BOULDER - With September in the rearview mirror for the Colorado Buffaloes, defensive line coach Mike Tuiasosopo says that's exactly where the freshman tag belongs for his trio of young interior players - in their backgrounds.

In Tuiasosopo's estimation, five games are enough for Josh Tupou, Justin Solis and Tyler Hennington to have learned how to assert themselves. He's also expecting more from junior Nate Bonsu, the lone upperclassman working the inside positions now that senior Will Pericak is spending most of his Saturdays on the perimeter.

"I just want them to understand, in my eyes the freshman thing is over," "Tui" said. "They need to play like veterans now. We're way beyond that. We've played in enough games and every one of them has had significant snaps. It's time for them to take their game to another level for us to be successful."

Tuiasosopo's message apparently came through unfiltered and very understandable for Solis, a 6-3, 305-pounder who at this time last season was playing for Westlake High School in Thousand Oaks, Calif.

"We need to 'man up' and start playing with more intensity, more drive and playing like we know we can play," Solis said. "Even though we're all young, we came in here for a reason - to help the team out. We've had to grow up fast with a lot of playing time and a lot of experience."

Solis has shared time inside with Tupou (6-3, 325), Bonsu (6-1, 289) and Hennington (6-3, 285). That quartet, said Tuiasosopo, needs to generate more of an interior pass rush before the Buffs return from their bye week to face Arizona State on Thursday, Oct. 11, in a nationally televised game from Folsom Field (7 p.m., ESPN).

"Our young guys have been up and down - but probably more up than down," Tuiasosopo said. "I know there's the learning curve with all those guys, but they've gotten a handful of games under their belts. They understand things a little bit better. At the beginning it was knowing what to do; now they know what to do and it's time for them to just really turn it loose. They need to play faster and more physical."

He said Tupou, of Long Beach, Calif., was "a little tentative" in CU's 42-14 loss to UCLA because of a lingering ankle injury and being held out of early week practices due to a concussion suffered in the previous game at Washington State. Tupou's only work preceding last week's game came on Thursday and "some of that showed on game day. When you play a team that's averaging 250 yards (rushing) a game you have to see it and feel the snaps in practice," Tuiasosopo said.

"To see it first on Saturday after not having any contact, that's hard to do. Coaches hold steady to 'you practice, you play' for a reason. For him not to have had those physical snaps (in practice) kind of showed up at the beginning of the game."

Solis and Hennington, a Mullen High School product, are "starting to figure things out now," Tuiasosopo said. "They need to be more explosive, more decisive in what they're doing. There's still a little bit of a hesitation on their part. They need to let it go."

Bonsu, of Allen, Texas, played in 12 games as a true freshman in 2009, then redshirted the following season after suffering a knee injury during winter conditioning work. He played in 2011 before undergoing postseason shoulder surgery that could have set him back.

But Bonsu didn't allow it to, successfully rehabbing the shoulder, rededicating himself in the weight room, and shedding almost 35 pounds before reporting to August camp. "It was pretty easy to put weight on after the shoulder surgery because I couldn't run," he said. "But I wanted to be in the best shape ever for camp and did a whole bunch of hard work, a whole bunch of 'Stairmastering' and just eating a little bit better."

Plus, he got an extra push or two from coach Jon Embree, Tuiasosopo and CU's strength and conditioning staff. "When I needed it, they gave it to me - and I was able to contribute to that," said Bonsu, who has started all five games this season before settling into a rotation with the freshmen.

Tuiasosopo said Bonsu "has been holding his own, but he's not playing at top end" due to a broken right hand suffered against Sacramento State and some recurring knee issues. Bonsu has played the last two games with his right hand in a protective cast. Still, Tuiasosopo's goals for Bonsu are for him to "make more plays and rush the passer better."

Bonsu's early playing time in '09 allows him to identify with what CU's first-year D-linemen are experiencing. "I told them before the UCLA game to let their hair down and have fun because I'd been in the same situation, playing as a freshman," he said. "I know how it can be."

The interior freshmen linemen "are definitely picking it up," Bonsu added. "You can see the strides they've made from camp until now just working on the smaller things. I can see that in myself as well. They're gaining more confidence in every game they play. I'm excited to see how all of them are going to be later on this year and in the future. They're going to be making big impacts."

Despite the Buffs' early September swoon and their 1-4 overall record (1-1 Pac-12), Bonsu said progress is being made. "What I would want people on the outside to realize is that we have a lot of really young guys and not just the freshmen - a lot of inexperienced guys in key roles," he said. "With that come growing pains. The first two games were close losses, the Fresno State game was a different story.

"How we got that road win at Washington State was special. I've been here for a while and know how scarce those were. I see improvement every week. I saw it last week (against UCLA). It's just a couple of mistakes and when you play a good team like UCLA you can't have them.

"There's a lot of good things going on here. There's improvement. We just need to stick in there and we'll be fine . . . the wins will start coming."

He said the Buffs are "holding together - and that's the biggest thing. When you go through something like this, you stick together because that's all you have. That's about as literal as you can put it. Each one of us, that's all we have. We've worked so hard through the off-season, through the summer. What we have is each other, and if we change the way this season is going we have to do it together."

Contact: BG.Brooks@Colorado.EDU