Now that it's tournament time, Missouri needs Arthur Johnson to return to the double-double machine he's been most of the season.

The 6-9, 265-pound center led the Big 12 with 15 double doubles (double figures in scoring and rebounds), but has been a curious non-factor lately. He had only two points and three rebounds in a 16-point loss at Iowa State, and also struggled in the regular-season finale with 11 points and seven rebounds against Kansas, a 79-74 loss on Sunday that denied the Tigers a perfect home record.

Coach Quin Snyder's fifth-seeded Tigers (18-9) open Big 12 tournament play today against 12th-seeded Nebraska (11-18) in Dallas. Snyder thinks Johnson's problem lately is more a case of extra attention from opponents than one of fatigue.

"I think sometimes you've just got to continue to stay strong mentally," Snyder said. "I'm not concerned he's worn down as much as I am that he just stays tough.

"That's the key for him, to fight through adversity, because he's going to see it."

Snyder said guard Rickey Paulding had a similar struggle earlier in the season.

"It's made him a better player," Snyder said. "It can take your game to a different level, but you almost have to embrace the difficulty of it in order to have it help you."

Johnson, who enters the tournament averaging 15.4 points and 9.2 rebounds, downplays his recent troubles. In the last three games, he's averaging 6.7 points and 5.6 rebounds.

"I'm still playing hard," Johnson said. "I don't know, it happens. Other guys have been stepping up and it's not like it's causing us to lose games."

Actually, Missouri is a so-so 5-5 in its last 10 games heading into the tournament and in need of a boost. The highlight, by far, during that stretch was a 67-52 victory over then third-ranked Oklahoma.

"We're looking forward to the Big 12 tournament," guard Ricky Clemons said. "I think we've got something to prove. But we know we can play with the best teams in the country."

The winner of today's game will face fourth-seeded Oklahoma State on Friday.

"Hopefully," Johnson said, "we do make noise."

The fifth-place Big 12 finish was Missouri's best in four years with Snyder. The Tigers are on track for a fifth straight NCAA tournament appearance, which would be the longest streak in school history, with an RPI of 23.