MOBILE, Ala. -- Florida running back Mike Gillislee had a number of outstanding runs Tuesday thanks to his nimble feet and a big offensive line. That made for a challenging day for the South linebackers.

Just as the quarterbacks in the 2013 Senior Bowl seem to be a crowded group with no clear-cut top option, the linebackers on the South team appear to be the same. Even with Stanford's Chase Thomas and Texas A&M's Sean Porter as the headliners, there are only a few discernible differences between the five men who practiced Tuesday. (Southern Miss linebacker Jamie Collins watched practice while resting a hamstring injury.)

If you had to rank them, it would be really hard, and that's coming from the man coaching them this week, Lions linebackers coach Matt Burke.

"They've brought in a pretty good level of talent," Burke said. "It's not like you've got a couple of guys that are way ahead of the pack. We've had some injuries and have had to move some guys around, so we're actually just shuffling guys in and out. The groups are all different, so they're kind of interchangeable, which is nice. I'm just rolling three different guys out there every set of plays."

That much was true during 11-on-11 drills, where Alabama's Nico Johnson manned the middle with Thomas and Porter on the outside. As the drills went on, Thomas stayed on the outside (usually the strong side) while Missouri's Zaviar Gooden and Florida State's Vince Williams manned the middle.

It was Williams who wound up making the most plays Tuesday, sniffing out a run out of a nickel package that drew cheers from Burke, then showing good quickness on a pursuit (if not an aggressive overpursuit) of a South player on another play. Finally, Williams intercepted a tipped pass for what would have been a touchdown had this not been a drill. Burke mentioned that Williams had "a good couple of days" following practice.

The coach also stressed that the linebackers need to be more physical Wednesday.

"I'd like to see a little more physical play," Burke said. "Today was our first day with pads on, and everyone's kind of tentative and feeling that out. Hopefully we've got that under our belt and tomorrow we have another full-padded practice. I'd like to see a little bit more poppin' and getting guys after it."

Notes on each linebacker:

  • Sean Porter appeared to be the most athletic linebacker of the bunch. Compared to his teammates, he did good work in run-stuffing, edge rush and especially pass-coverage drills. In 11-on-11 drills, he worked exclusively as a weak-side linebacker, which plays to his strengths. No one will confuse him with Von Miller, but he's got the most promise of this group.

  • Vince Williams was second-best Tuesday among the linebackers, though he didn't show off his skills until the 11-on-11 drills as described above. He didn't stand out much in the other practice sessions, save for some flashes in edge-rush work and chasing down offensive players. He played on the inside Tuesday, just as he did at Florida State, and he'll likely find some work there as a third-day pick.

  • Zaviar Gooden is known for his wheels, not necessarily his physicality. He didn't do much to stand out Tuesday as the second-team weakside linebacker behind Porter. Getting off the snap in edge-rush drills might have been his best work as he struggled to wrap up Gillislee a number of times in 11-on-11. He also seemed to struggle in pass coverage a few times. The good news is that he's got excellent athletic traits that might just need some harnessing.

  • The first thing that stands out about Nico Johnson is that he passes the eyeball test at a big 249 pounds. The inside linebacker had a non-descript practice, not distinguishing himself as anything more than what he's been scouted as: A physical run-stopper.

  • Speaking of looking the part, no linebacker was as physically imposing as Chase Thomas (6-foot-3 1/8, 241 pounds). The outside linebacker practiced and played with a lot of effort, throwing around fellow linebackers in a tackle-shed drill, and that helped make up for a lack of burst and speed that a lot of high-profile outside linebackers tend to have. On Tuesday, Thomas was beaten a number of times on a quasi-race from a two-point stance to a tackling dummy. Ultimately, he seemed a half-step behind receivers in practice and a bit slower than his teammates in drills.