One of the key ingredients to the Colorado basketball team's success last year was having a stellar sixth man in Askia Booker coming off the bench.

Coach Tad Boyle hasn't found that steady presence that Booker provided to this point this season. It's just one of the issues Boyle is tackling as he tries to get his team back on track after it started Pac-12 Conference play 0-2 last week against the Arizona schools.

It might not be the top issue on Boyle's list, but it sure would help having a player to count on for consistency and energy off the bench every night.

Senior Sabatino Chen and freshman Xavier Johnson would both rather be starting. What player wouldn't? But both are willing to try to fill that role if the task falls to them.

It has been Johnson's responsibility much more often than Chen's so far this season, but the one time Johnson was in the starting lineup and Chen came off the bench, Chen had a career game and the Buffs nearly beat No. 3 Arizona on the road.

"Here's the deal, we're 0-1 with Xavier Johnson starting in the Pac-12 and we're 0-1 with Sabatino Chen starting in the Pac-12," Boyle said after Tuesday's practice. "We got out of the blocks good at Arizona with Xavier starting and we started out 17-4 at Arizona State with Sabatino starting.

"So that has nothing to do with it. It doesn't matter. I've talked with both young men about it and told them they have to understand it might change game to game and it's all based on matchups."

As of midday Tuesday, Boyle said he still hadn't decided which player would be best to start against USC on Thursday night at the Coors Events Center. The Buffs also host UCLA on Saturday in a pair of important league home games.

CU could be in a much better position in the conference if it can earn two victories this week in its arena where it boasts one of the best home-court advantages in the Pac-12. Chen and Johnson said they would be ready to go regardless of what role Boyle asks them to fill.

"I'm not against coming off the bench," Chen said. "Whatever makes our team play the best, that's what I want to do. If coach tells me he thinks we'll have a better chance if I come off the bench, I'll come off the bench, but like coach says, it's not about who starts the game. It's about who finishes the game."

Chen said the Buffs have been missing the sixth man role Booker filled so well last season, but he sees it as a larger problem with the whole bench. He said if the Buffs are going to get where they want to go they need eight or nine consistent players on both ends of the court.

Johnson admits he prefers starting to coming off the bench because he knows going into the game exactly when he has to be ready and what his assignment will be. Coming off the bench is more of a guessing game in terms of when his number will be called and who he might matchup with based on who is on the floor.

Johnson said all good players have to learn to adjust to the circumstances and that is something he is focused on improving in his first season at the college level.

"I'm trying to be that spark plug coming into the game," Johnson said. "Instead of staying steady in the game, I come in and score more points, get more buckets and do more for the team."

Boyle addressed a lot of fundamental points with his team during Tuesday's practice. Afterward he said one of the Buffs' biggest problems is consistency.

"What we are not doing is we are not playing consistent basketball from start to finish," he said. "That's why we're 0-2 (in Pac-12 play).

"It has nothing to do with hangovers from Arizona or not being ready to play or who we're starting. It's all about can we sustain something for 40 minutes and right now we're not on the defensive side of the ball and rebounding. We're not sustaining things."

Notable

Booker sat out the last 30 minutes of practice Tuesday after bumping his knee. Boyle said it wasn't serious. "Ski will be ready to go come Thursday," Boyle said. "I can promise you that." ... Boyle said Tuesday's practice was "a good, long, spirited, competitive practice, which is what we need."