Just when Lawrence Thomas thought he'd found a permanent role on the Jets' roster, Dimitri Flowers came around.

Thomas, entering his third year in the NFL, started last season as a defensive lineman. But after getting a bit crowded out by the Jets' depth in that spot, he switched to fullback midseason - a move thought up by head coach Todd Bowles, given the team didn't have a natural fullback.

The move worked; Thomas played 14 games last year, tallying a run and a handful of receptions. And the switch seemingly made Thomas' job safe.

Then the Jets signed Flowers.

Now, there's competition. And the 286-pound D-line convert is up against an undrafted rookie that just spent four years playing nothing but fullback at Oklahoma.

So what has Thomas been doing to prepare for the battle? It's all about the feet.

"Being a defensive lineman, a defensive person, the footwork is way different," Thomas said. "So just being an offensive guy, you have to clean up your feet a lot more, so being light on my toes and just being able to run my routes crispy and being able to flow smoothly. So that's what I'm working on right now."

The bright side for Thomas is that, unlike last year, he's had a full offseason to train as a fullback this time around, which has helped simplify and clarify his preparation.

"I attacked my offseason like I was supposed to," Thomas said. "I focused on one position and just doing all the drills that I need to do - ladder work, just on a treadmill running up hill and doing the little things that are going to allow me to be faster, explosive."

Thomas moves well for a big man, but quickness is an understandable point of emphasis given he's competing against a fullback who's 40-pounds lighter.

But the flip side of that coin is exactly what has Flowers a bit worried so far.

"Really, obviously LT coming from D-line, what he does, how big he is, (we are) different in terms of physicality," Flowers said. "Of course, myself, coming from a spread offense in college, I didn't really do a lot of that. So I'd say that's the biggest thing, but like I said I'm trying to improve my physicality as well."

Physicality is a buzzword for Flowers, who knows he'll have to bone up on his blocking in order to beat out the big-bodied Thomas.

And strangely enough, one area where Flowers should logically have an edge over Thomas - catching the ball - given Thomas' limited experience on offense, doesn't seem to be much of an edge at all.

"I put emphasis on it a lot during the offseason, but I've been known for catching the ball pretty well, even in college and high school," said Thomas, who played fullback as a freshman at Michigan State. "So it's another thing I have to add to my game, make sure I stay on top of."

"(Catching the ball) is one thing I take pride in, that's one thing I have to be successfully in - especially in order to beat him out because he can do it as well," Flowers said. "That's just one of those things where I just have to go out there and showcase it."

Really, then, this battle may just come down to which fullback displays the balance of speed and power, quickness and strength, that the Jets are looking for.

Another factor? Versatility. The Jets certainly don't intend on having Thomas play on the other side of the ball again, but knowing he's capable of playing special teams or moving to defense in a pinch certainly can't hurt his chances.

For now, though, both players are locked in on offense and grinding toward a spot on the 53-man roster for Week 1.

"Right now, we're just both competing," Thomas said. "We come day in and day out and just focus on the job at hand every single day. I can't step ahead of myself and call out my advantages and everything. I'm going to come every day, work real hard and see what's at the end of the tunnel come the end of preseason."

Matt Stypulkoski may be reached at mstypulkoski@njadvancemedia.com. Follow him on Twitter @M_Stypulkoski. Find NJ.com Jets on Facebook.