A look back at the happenings across the Big 12 this weekend.

Sooners lose another starter

It's been a less-than-ideal offseason for Oklahoma, which heads into the fall as one of the favorites to win the national title. It got even less ideal when starting right tackle Jarvis Jones suffered a ruptured patellar tendon in his knee.

"We were in a team period and it just buckled on him," coach Bob Stoops said in a release.

Jones started four games last season, but he's expected to miss six months and return in late September or October. That's a big deal for the Sooners, who play at Florida State, a likely top five opponent, on Sept. 17. If Jones can get ahead of schedule on his rehab, it wouldn't be shocking if he returned by then, but it's another setback for the Sooners.

Three starters had run-ins with the law before spring practice, and All-Big 12 cornerback Jamell Fleming, the team's best cover man, is not currently enrolled at Oklahoma after reported academic dishonesty. His future is still in flux, and though none of the offseason happenings are complete game-changers, they're all unnecessary distractions for the Sooners, who have admitted themselves that this season is all about gunning for the national title.

Baylor defense bounces back

Baylor's defense couldn't have played much worse in the team's last scrimmage, but new coordinator Phil Bennett had to be pretty happy with the effort in a weekend scrimmage.

The Bears had eight sacks and scored three touchdowns. Defensive end Willie Jefferson, a converted tight end, led the team with three sacks and scored on a 30-yard fumble return. Jared Edwards also had a pair of sacks.

"I thought we made some strides this week. I think we are starting to get some people in the right positions," Bennett told reporters after the scrimmage. "As I told them, we aren’t there yet, but I saw some steps. We put them in some tough situations. We moved the ball downfield, we did some red zone with one minute and they responded better. But like I said, we are not there yet. I told the guys that if we can stay on an even keel with our offense, we are going to get better and win some games.”

Terrance Ganaway put up a nice stat line with 42 yards on seven carries and a touchdown, and Darius Jones led all receivers with 70 yards on six receptions.

Kicker Aaron Jones struggled down the stretch after a fast start last season, but he was 4-of-5 on field goals, including a 57-yarder and another from outside 50 yards.

Oklahoma State sits Markelle Martin for spring surgery

Safety Markelle Martin should be one of the leaders of Oklahoma State's defense next spring, but Oklahoma State elected to end his spring for shoulder surgery.

"We cleaned his shoulder up,” coach Mike Gundy told reporters. "He really didn't need the surgery right now, but there was no reason [to delay the surgery], because we have a lot of depth at safety."

Top among those remaining safeties is Daytawion Lowe, who missed all of last season with a knee injury, but has impressed throughout the spring. Lavocheya Cooper is listed behind Martin at strong safety on the spring depth chart.

Cyclones snatch another Knott

Linebacker Jake Knott is already one of Iowa State's best players after making 130 tackles in 2010, third-most in the Big 12.

Now, his little brother, quarterback Luke Knott, is ready to follow. The native of Lee's Summit, Mo., gives Iowa State two 2012 commitments, both quarterbacks.

California native Grant Rohach committed to the Cyclones this month.