– After Roc Thomas signed with the Vikings in April, it didn’t take long for the undrafted free agent to fixate on a player he thought he might be able to use as a template: Jerick McKinnon.

The former Vikings running back had signed a four-year, $30 million contract with the 49ers in March, after blossoming into a role as a runner and receiver and posting 991 yards from scrimmage in the Vikings’ offense. Thomas saw how the Vikings had used McKinnon, what they were going to be missing and realized he might be able to succeed in Minnesota by imitating a bit of what the former third-round pick had done.

“Coming in, and seeing Jerick left, I was like, ‘OK, they like these types of running backs: the versatile running backs that can catch out of the backfield, that can outrun guys, that type of stuff,” Thomas said on Saturday night. “I watched some film on him. [Running backs] coach [Kennedy Polamalu] talked to me about him, letting me know how he carried himself and stuff like that.”

There are more than a few steps between where Thomas is now and the role McKinnon played in the Vikings’ offense last year. He first has to win a spot on the Vikings’ roster, beating out such backs as Mack Brown and fellow rookie free agent Mike Boone, and then has to earn playing time as the third running back on a team that expects to lean on a healthy Dalvin Cook and utilize Latavius Murray.

The plays Thomas made on Saturday night, though, could help him move in that direction.

He posted 130 yards from scrimmage in the Vikings’ preseason opener against the Broncos, scoring the team’s second touchdown on a wheel route from Trevor Siemian and making the biggest play of the night on a screen pass, taking advantage of a block from Aviante Collins and following Josh Andrews and Cedric Lang before breaking away at midfield on his way to a 78-yard touchdown.

“I just saw a lot of green,” he said. “I think today was a good showcase of my versatility, coming out of the backfield catching the ball and running between the tackles.”

A prized recruit coming out of Oxford, Ala., Thomas signed with Auburn but transferred to Jacksonville State after two injury-plagued years moved him down the depth chart. He had 1,309 yards from scrimmage on 199 touches last year, and though the performance wasn’t enough to get him drafted, Thomas got a $10,000 signing bonus and another $13,000 in guaranteed money from the Vikings.

Pre-draft evaluations of Thomas centered on whether he’d be patient enough to let plays develop, rather than trying to turn each run into a big gain. To improve his footwork, Thomas took up boxing.

“[It helps with] a little patience on the footwork,” he said. “Boxing, you get that footwork right, you can dance, man.”

Thomas missed time early in training camp with an injury, and he’ll need to be both healthy and consistent to lock down a spot on the roster. He could find additional opportunities in the preseason, especially if the Vikings continue to exercise caution with Cook on his way back from a torn ACL, but offensive starters figure to play longer in the next two preseason games than they did Saturday night.

The Vikings regularly have kept three running backs, though, and there seems to be a good chance they’d do so again, especially if they want to be judicious with Cook’s workload early in the season.

Thomas’ big night came after Boone appeared to give up a sack on Siemian when he was late to react to an inside blitz in the second quarter. Brown limped off the field in the fourth quarter, with the Vikings’ athletic training staff examining his right leg on the sideline.

It meant Thomas would have time to make a strong first impression in his Vikings debut. And in doing so, he delivered hints that he might be able to provide some of what the Vikings could miss without McKinnon.

“My whole train of thought [before the game] was, ‘Go in, just try to get your feet wet,’ ” Thomas said. “But I got my whole body wet.”