"I always had the idea that if I could get the opportunity to go out there and showcase my talents, I could shock the coaches," Thigpen said. "They don't know what I can do, because I haven't been in this position. Once they can give me the opportunity, I can definitely show them."
Including runbacks, Thigpen has had five gains of 50 yards or more in his brief career, which underscores his breakaway ability.
"Marcus is a talented guy," quarterback Ryan Tannehill said Wednesday. "We've all seen his speed flash at certain times on special teams. He's a weapon we can use in this offense. It's going to be exciting to see what he can bring to the table."
A 5-foot-9, 195-pound scatback, Thigpen will give the Dolphins' ground game a different look, which could be a good thing. With their line depleted by the team's bullying scandal and center Mike Pouncey's stomach illness, Miami has totaled 158 yards rushing over the past three games.
For the season the Dolphins rank 26th in the rushing. On Sunday they'll face a Jets run defense that ranks No. 1 in yards allowed per game (72.6) and per carry (2.9).
The lack of a ground threat has allowed opposing pass rushers to tee off on Tannehill, who has been sacked a franchise-record 44 times.
"We've got to help our quarterback out by running the ball," said Pouncey, who expects to rejoin the lineup after missing the past two games.
Thomas' injury could mean more work for Miller, a second-year pro who has never carried more than 18 times in a game. He said a heavier workload would be fine with him.
"I'm pretty sure any running back would love it — getting in the groove and getting more comfortable, knowing they're getting the ball more," Miller said.
Mike Gillislee, a fifth-round draft pick from Florida, becomes the No. 3 running back and might make his NFL debut. Gillislee is 5-11 and 210 pounds, while the faster but smaller Thigpen concedes he's not going to bowl tacklers over.
"I'm mainly a speed back," Thigpen said. "I like to get in the open field and make people miss and try to take it the distance."
A Detroit native grew up a fan of Barry Sanders, Thigpen also found it easy to root for Foster, a former practice squad player who became a 1,600-yard rusher for the Houston Texans in 2010.
At the time Thigpen was playing for the Hamilton Tigers-Cats of the Canadian Football League, awaiting a shot at the NFL. It came last year, when the Dolphins signed the former Indiana all-purpose star.
As a rookie, Thigpen became the first Dolphins player to return both a punt and kickoff for a touchdown. His biggest play from scrimmage has been a 50-yard reception this season against New Orleans.
Now he's eager to carry the ball — and bracing to block 230-pound linebackers when he's handling blitz protection.
"That's going to be a tough challenge," he said with a laugh, "but I'm ready for it."