File photo/Arizona Daily Wildcat Junior center Kirk Walters struggles for two of his eight points in the Wildcat's win over UAB in Boise, Idaho, March 19.

In this edition of Pastner's Notebook, Arizona men's basketball assistant coach Josh Pastner talks about the status of the Wildcat big men.

Wildcat: With (former center) Channing Frye gone, there are some really big shoes to fill. Is Kirk Walters, who worked out with Los Angeles Clippers center Chris Kaman over the summer, ready to step into a bigger role?

Pastner: Kirk has really made some great strides. From where he was as a freshman to where he is now, he's 180 degrees better than people could have ever believed back when he was a senior in high school.

With his work ethic in the weight room, he's really made strides that are tremendous, and he's able to be a big-time player at the Pacific 10 level. He has the opportunity to help Arizona win a lot of games.

Wildcat: How much did Channing Frye's presence help Walters with his game?

Pastner: Channing was great for him. You have a top-10 (NBA draft) pick working out against Kirk every single day for two straight years. It was great. He was able to kick Kirk's butt a lot of times, and sometimes Kirk needed it.

Sometimes, that's what players need. They need their butts kicked to really learn and to really get better and to really grow, and that's what happened with Kirk. Kirk became more aggressive, attacked the rim more and tried to dunk everything under the hook, because in order for him to compete against Channing, he had to do that.

The key (aspect) that Channing has over Kirk right now is that he's able to maintain playing at a high level for a long period of time, consistently, straight. That's something that Kirk has to get to, where he's not (playing) in spurts. He has to be able to play eight, nine, 10 minutes straight at a high level without any slippage in the level of play.

Wildcat: (Junior forward) Ivan Radenovic spent his summer working out in Serbia-Montenegro. He has improved every year and had a big role on the team last year. Does he have NBA potential?

Pastner: He definitely has NBA potential because he is so versatile, because he can shoot, he's smart, he knows the game, he knows how to play, and that makes him much more attractive to the NBA scout. He's only a junior and, once again, he's another player who has made strides from his freshman year.

For Ivan to make sure that he is going to be a solidified NBA guy, he obviously has to get through two more big years here and then has to keep improving on his athleticism. He has to keep being a great shooter. I think last year at times he was inconsistent, and he needs to become a consistently great shooter night in and night out.

Wildcat: A lot of European players get knocked for being bad defenders, but that does not seem to be the case with Ivan.

Pastner: He improved in his defensive abilities and his rebounding abilities because he improved his athletic abilities, and that's something he has really worked hard on in the weight room to improve himself as an athlete, which he did. That's why he's able to play at a high level against great athletes on the defensive and offensive ends and on the glass. He needs to improve his athleticism even more so he can guard a three man (small forward) on the perimeter consistently.

Wildcat: The big guys ran a high-low offense last year. Will that continue, and what do they need to do to be effective in that offense?

Pastner: Because of our versatility between our one through four men (in order: point guard, shooting guard, small forward and power forward), we have four guys on the perimeter who can play multiple positions, and that makes the way we play so attractive. It makes it tough to guard, for the opponents to match up, because our guys can play inside and outside and score all over the floor.

We will do some high-low stuff (this year), but I think we want to keep making it as tough for the opponents to match up with us.

Wildcat: Moving on to Isaiah Fox, he looks like a completely different person this year.

Pastner: Isaiah is a new, changed man. He looks great, his body looks great and he's in great shape. He has to really work on finishing shots around the hoop. That's his most important thing. He looks great, he's worked his tail off and I'm proud of him.

We need him to step up. In order for us to win games, we need him to step up and produce for us, so we're counting on him to do that.