Xavier's men's basketball team will start the Big East Tournament without junior center Matt Stainbrook. Coach Chris Mack said Stainbrook has done "a great job with his rehab" since straining the MCL in his left knee against Seton Hall last week, but he'll be unavailable for Thursday's 9:30 p.m. quarterfinal against sixth-seeded Marquette at Madison Square Garden in New York. Stainbrook's earliest return would be Saturday, should the third-seeded Musketeers advance to the conference championship. "He's really diligent. He's been in our training room twice a day since the injury. But we were told from the beginning to not even think about Matt returning until 10 days, and at 10 days they would re-evaluate. That would put us at Saturday," Mack said Monday on the Big East coaches' conference call. "Obviously that doesn't help us for Thursday night or the possibility for Friday but we've known that from the beginning, so we'll be playing without Matt on Thursday with the hopes that we can advance to the final. At that point hopefully we can get him in uniform and he'll be able to play." Stainbrook missed the Musketeers' regular-season finale against then-No.6 Villanova and was regarded as day-to-day until Mack's announcement. It's tough news for a Xavier team facing frontcourt challenges in Marquette players like Davante Gardner. The 6-foot-8, 290-pound senior and two-time Big East Sixth Man of the Year averaged 17.5 points against Xavier in the teams' regular-season split. Foul trouble sidelined Stainbrook for some of the teams' most recent meeting, an 81-72 Marquette win in Milwaukee. Jalen Reynolds helped fill the void, logging 14 minutes and finishing as Xavier's top offensive rebounder. Reynolds has played the best ball of his freshman season in his last nine games. What's more, his top overall outing came against St. John's in the same arena Xavier is about to play the Golden Eagles. Reynolds erupted for 17 points and 16 rebounds in the Feb.25 victory at Madison Square Garden. "There's no doubt he has improved immensely, and we need him to. He's going to be going against two senior post players (in Gardner and Chris Otule). Three senior post players if you count Jamil Wilson as a post, even though he floats between the three and the four. So he's going to have to play with a lot of toughness," Mack said.