Preseason lore is filled with exhibition warriors who can't cut it in games that count. They conquer during the summer, wither in the fall and are left out in the cold by winter.

We won’t know where New England running back Jeff Demps fits into that picture until the regular season begins, but it’s hard not to anticipate the possibilities after his performance during the Patriots’ 30-28 loss to Tampa Bay on Friday night.

“Coach (Bill Belichick) put him in a position to make some plays out there both in the return game and at running back,” quarterback Tom Brady said. “It's pretty amazing to go from what he was training for the last six or eight months of his life, and to come here and put pads on and do the same thing.”

Signed last weekend, Demps, who won a silver medal this summer at the London Olympics as a member of the 4 x 100 relay team (he ran in one of the heats, not the final), was forced to operate from instincts, and he could be seen on several plays asking teammates where he was supposed to line up. His inexperience was further reflected by the procedure penalty he drew on his first offensive play. But once the ball was in his hands, his legs took over.

After being drilled on the sidelines when attempting to turn up field on a sweep, Demps settled in and broke a 29-yard run up the middle, seemingly arriving in the second level immediately after hitting the hole. He later added 9 more yards on another run between the tackles to finish with 41 yards on 3 carries.

Demps also returned two kicks for 44 yards, had a 24-yard punt return negated by a penalty and was sent on a variety of screen and wheel routes. He finished without a catch, despite being targeted three times.

While most had positive reviews for the rookie, Belichick took a different approach and bluntly stated that Demps “has a long way to go.”

He does, but he may just get there.

Offensive line struggles again: The struggles of the offensive line have been the prevailing theme of the preseason, and that didn’t change Friday night. The team used three different players at center and got shaky play from right tackle Marcus Cannon. Brady, who played into the third quarter, was forced to endure several huge hits.

The good news is that the cavalry is coming. Left guard Logan Mankins (knee) and right tackle Sebastian Vollmer (back) both dressed for the first time after starting camp on PUP. Mankins played two series before taking a knee, but Vollmer never got off the bench.

Injuries mounting: Running back Shane Vereen (left foot), fullback Spencer Larsen (knee), safety Steve Gregory (thigh) and cornerback Kyle Arrington (unknown) all suffered injuries.

Vereen, Larsen and Arrington all retreated to the locker room and did not return. Gregory remained on the sidelines after colliding with cornerback Ras-I Dowling in the third quarter.

Mallett shines: Ryan Mallett continues to close the gap on backup quarterback Brian Hoyer. Following a strong performance against Philadelphia (10 of 20, 105 yards), Mallett entered the game in the fourth quarter of Friday’s game and completed 7 of 13 passes for 66 yards with 2 touchdowns. Hoyer did not play.

After the game, Belichick said that no decisions have been made on who will serve as the backup.

Nick Underhill covers the Patriots for MassLive.com. Follow him on Twitter @CBSSportsNFLNE or @nick_underhill.