Summer Shootaround: Big Ten

Editor's note: ESPN.com’s Summer Shootaround series catches up on the offseason story lines for each conference. For more on the Big Ten, click here.

Five offseason story lines in the Big Ten...

1. Nix gets arrested, vows to bounce back: Derrick Nix turned his entire Michigan State career around last season. Red flags had followed the big man in his first two years. His weight had been a burden. He'd previously threatened to quit the program. In Year 3, however, he had become a leader and he'd slimmed down. But an April drug-related arrest and subsequent suspension was a major setback for Nix and the program, which lost Draymond Green. Green was one of the most versatile players in America. He was also recognized as one of the country's top leaders. This season's Spartans possess top-10 talent, but they need Nix to recover from April's mishap. Improved conditioning will help the program's only returning senior play more than last season's 18.9 minutes per game and improve his overall numbers (8.1 ppg, 3.1 rpg). The veteran has to make the most of a second chance.

2. A healthy Aaron Craft: For the past two seasons, Craft has been one of the nation's toughest perimeter defenders. Jared Sullinger anchored the offense the past two years, but Craft (8.8 ppg, 4.6 apg, 2.5 spg) has been the defensive catalyst for a team that finished second in Ken Pomeroy's adjusted defensive ratings last season, even though he wasn't healthy. Earlier this month, the Columbus Dispatch reported that Craft underwent surgery in June to repair bone chips in his ankle that Craft's father said "would get jammed back on his tibia and it would cause excruciating pain." Craft had dealt with the pain since high school but refused to correct it prior to this summer. He is missing six weeks of offseason drills, but he should be healthy and prepared for the upcoming season.

3. The John Groce era faces early hurdles: In March, Illinois dismissed Bruce Weber following 12 losses in the program's final 14 games. Enter John Groce, who led Ohio to the Sweet 16 in March. It wasn't the name most had anticipated, although he's highly respected among his colleagues. But his tenure got off to a rough start. Meyers Leonard declared for the NBA draft. Isaac Chew, an assistant who left Missouri to join Groce's staff, left Illinois two months after accepting the job to become an assistant at Marquette. And last week, Chicago native Jabari Parker -- the consensus No. 1 recruit in the 2013 class -- named 10 schools he's still considering, and Illinois wasn't on the list. But Groce's resume suggests that the early bumps won't last. He turned Ohio into a mid-major power that nearly upset North Carolina in the NCAA tournament. The former Ohio State assistant helped the Buckeyes recruit Greg Oden, Mike Conley Jr. and Daequan Cook, a trio that led the Buckeyes to the 2007 national title game.

4. Trey Burke claims Michigan can win national title: For weeks, Burke (14.6 ppg, 4.6 apg) considered the NBA. But he ultimately made a wise choice to come back for his sophomore season and he's now arguably the top point guard in the country. Last week, he told the Detroit Free Press, "I really think we're national championship contenders." And he's right. His return positions the Wolverines to compete for the Big Ten title and make noise on the national scene. Had he decided to leave, a Michigan program with the 14th-ranked recruiting class in 2012 would have lost its point guard for the second consecutive season. The incoming crew features Mitch McGary and Glenn Robinson III. Plus, Tim Hardaway Jr. is back. With Burke in charge again, the Wolverines might reach Atlanta, site of the 2013 Final Four.

5. Bigger, better Zeller: Had Cody Zeller (15.6 ppg, 6.6 rpg) entered the NBA draft, he probably would have cracked the lottery. But he's in no rush to end his collegiate experience. And now he's the leader of an Indiana team that could enter next season as a favorite to win the national title. Coach Tom Crean says the 7-footer has expanded his game and will showcase more versatility this season. During summer workouts, Crean has implemented more pick-and-roll situations for Zeller. He told ESPN.com the sophomore will put the ball on the floor more often than he did last season. He's also adding muscle. Zeller will probably win multiple preseason player of the year awards in the coming months, and he's putting in the work this summer to justify those expectations.