FOXBORO -- Once the Patriots traded AJ Derby to the Broncos for a fifth-round pick earlier this week, they were left with just two tight ends on their roster. While those two tight ends -- Rob Gronkowski and Martellus Bennett -- have played as two of the best tight ends in football this season, it's a position group that has been considerably thinned.

Until coach Bill Belichick adds another player at that spot, James Develin would be the logical "next man up." A position group unto himself as the team's lone active fullback -- the other fullback in the locker room is practice-squad player Glenn Gronkowski -- Develin meets with Patriots tight ends and coach Brian Daboll on a daily basis because the fullback and tight-end responsibilities in the Patriots offense are similar, particularly in the run game.

As much time as he spends with that group, Develin tries to absorb what he can when it comes to the nuances of the position.

"I always kind of try to prepare, obviously, for my fullback role, but then in any other role that I might be called upon for," Develin said on Thursday. "A couple years ago, we had a bunch of injuries during the offseason program, during OTAs, and I filled in a little bit at tight end. I try to keep myself familiar with all those techniques and that tight end role so if the day were to come where I needed to go out there and do it, I'd be able to go out there and do it."

When the Patriots began the season relying more on the run, Develin was called upon to play a relatively significant role in the offense. He averaged 21.3 snaps per game through the first three games of the season, but that number has fallen to 13.6 since Tom Brady's return from a four-game suspension. Still, his role can be a critical one.

The Patriots' running game faltered last season after both Blount and Dion Lewis went down with season-ending injuries. Having Develin in the mix as an extra blocker would not have guaranteed a more efficient attack, but it may have helped the team's running-game woes late in the year.

Offensive coordinator Josh McDaniels now has the luxury of bringing Develin onto the field when he wants some added muscle for his blocking schemes, and should the Patriots need a tight end in a pinch, Develin could do that too.

"A lot of times, especially in the blocking game, really the only difference [between fullback and tight end] is that I'm five yards off the ball in the backfield and they're up on the line," Develin said. "The angles are a little bit different. But a lot of times the assignment is typcially the same thing. It's just the technique of getting there and the angles that you take.

"Then in the passing game, as a tight end, there's just a lot more routes and stuff like that. I try to work on that to help me as a fullback to be a little bit better in space . . . It's a sybiotic relationship."

As it is, Develin will line up occasionally outside. Though not a threat as a receiver in that spot in the same way that Gronkowski or Bennett would be, he understands some of the different looks tight ends have to be comfortable with.

If an emergency arose and he was asked to fill that role, he wouldn't hesitate.

"There's a little bit of carry-over depending on what we're doing or whatever play we have called where I'll line up on the line," he said. "But that's kind of what a fullback has to do. You kind of have to be able to be thrown into whatever position on the field that you gotta do and you gotta just do your job."