Former Los Angeles Chargers fullback Derek Watt couldn't pass up the opportunity to play with his younger brother T.J. It's the main reason he agreed to a three-year contract with the Pittsburgh Steelers.

PITTSBURGH — Turns out, Derek Watt's reunion with younger brother T.J. has its limits. Like say, sharing a roof for the first time since college.

“I know (T.J.) doesn't want that,” Derek Watt said with a laugh on Thursday, about a week after agreeing to join T.J. on the Pittsburgh Steelers. “My wife doesn't want that (either).”

It may be one of the few respites the two get from each other after Derek signed a three-year deal to join T.J. in Pittsburgh. While Derek admits the chance to share the same locker room with T.J. — something the two did in both high school and in college at Wisconsin — played a factor in his decision to head east after four years with the Chargers' organization, it wasn't the main reason the fullback chose the Steelers over a handful of other interested teams.

“The culture they have there, the tradition they've built, I just feel like it kind of fits into the way I was raised,” Watt said.

It helped that the Steelers — unlike many NFL teams — still find room on their roster for a fullback. Rosie Nix was a Pro Bowler in 2017 while opening holes for Le'Veon Bell. Pittsburgh has long placed a premium on versatility. In addition to working out of the backfield, Watt was a standout on special teams with the Chargers and dabbled a little at tight end.

While Steelers coach Mike Tomlin declined to get into specifics with Watt on what role he expects to fill, Watt understands he needs to be willing to put his hand in whatever pile Tomlin points him to. It's part of the territory when you're 6-foot-2 and 235 pounds, making you the “littlest” brother in the Watt family.

“As a fullback in the NFL, you better be a core special teams guy,” Watt said. “As a fullback in the NFL you have to play special teams, you don't get those reps in games as often. That's just the nature of the sport.”

Watt spent the majority of his time with the Chargers. He has 29 career touches for 201 yards and one touchdown — or one more than T.J., an outside linebacker and four fewer than oldest brother J.J., a five-time All-Pro defensive end for the Houston Texans.

Derek Watt admitted J.J. is jealous that he won't get to play alongside his brothers, though all three could share the field this season when Houston visits Heinz Field. Though Steelers' fans have inundated J.J. on social media pleading for him to find a way to make it to Pittsburgh, for now they'll have to settle having two-thirds of the family.

“Bring the three of us, the trilogy all together, that would be something special,” Derek Watt said. “I'm not the big sexy signing that J.J. would probably be, but I plan to do whatever I can to not let those fans down.”