TULSA, Okla. (AP) - With a logjam in Boise State's backfield, Doug Martin had become expendable.
There were too many backs and not enough carries, and he ended up getting groomed into a new role on defense this season.
An injury and an illness later, he's once again an essential part of the Broncos' offense.
When D.J. Harper suffered a left knee injury in Boise State's third game of the season, coach Chris Petersen made the move to bring Martin back to the offense in what would be a bittersweet switch.
"It was real unfortunate that D.J. went down," said Martin, a sophomore from Stockton, Calif. "We're real good buddies. We've been buddies since I first got here.
"I'm just carrying the flag for him. It's been a really nice experience, and I'm just going to keep doing it for him."
Martin surpassed 100 yards rushing for the second time in three games when he ran for 112 in the Broncos' 28-21 win Wednesday night at Tulsa.
With Boise State (6-0) up only 15-14 at halftime, Petersen turned to Martin to carry the load in the second half. Martin got the ball 12 times on the Broncos' first two drives of the third quarter, and he made the most of it.
Martin ran around and through Tulsa's defense for 83 of his team's 104 yards rushing in the third quarter as Boise State scored the period's only 10 points. Petersen said he relied on Martin even more because starter Jeremy Avery was "under the weather."
"He's kind of a power runner and he'll break tackles and he'll slam it up in there," Petersen said. "I think he and Jeremy are a good 1-2 punch."
Martin had only 24 carries for 107 yards all of last season, but he made a mark elsewhere. He earned the "Hammer" award as the most physical special teams player on the team, then shifted to defense during spring practice.
He's slowly been taking on a bigger load since moving back to offense, getting 13 carries against Bowling Green and then 16 against UC Davis.
Martin carried the ball a career-high 23 times against Tulsa and was called on five straight times to start Boise State's second drive after halftime. He racked up 42 yards and also drew a 15-yard facemask penalty as he moved the Broncos into field goal range.
"It's a lot better. Last year, when I shared with (Ian Johnson) and D.J., it was like we couldn't get a rhythm," said Martin, who had a career-best 116 yards against Bowling Green. "I think it was a lot better getting play after play after play, getting the feel, getting the rhythm, the speed of the defense and just the speed of the game in general. I think it was a lot better that way."
Behind Martin's running, the Broncos were able to take control of the game and build a big enough lead that Tulsa (4-2) couldn't come back.
"The difference probably in the game was their ability to run the football, and they didn't do it by lining up and just running right at us," Tulsa coach Todd Graham said. "They did a lot of movement and things like that, and they're very, very well coached and do a great job of displacing you on defense."
Avery complemented Martin with 16 carries for 73 yards as the Broncos ran for 193 yards - just over the 191.6 yards they had been averaging.
"Doug's a good player. He's a hard-nosed player and fortunately for us, losing a guy like D.J. Harper, Doug is a similar type back to him," Petersen said. "He's a strong, tough runner and we were crushed when we lost D.J. But on a positive note, we really felt like Doug could pick up the baton and we wouldn't miss a beat, and he's a heck of a running back."