MANKATO -- Rookie first-round draft pick Cordarrelle Patterson already has the kickoff return job locked down. Now, the Vikings are contemplating whether or not to give him some reps at punt returner in Friday's preseason game against Houston at the Metrodome.

At this point, incumbent Marcus Sherels is the No. 1 punt returner. But he also could lose his grip on that job because he might not make the team as a reserve cornerback. That has the Vikings preparing to audition other candidates when they finally get some live action on Friday.

"We have a few different guys," coach Leslie Frazier said. "We want to take a look at Stephen Burton a little bit. We're probably going to give Bobby Felder a chance. We're debating about whether or not we want Patterson to have a chance to do it as well. Jarius Wright may get an opportunity. So we have a few candidates to potentially take a look at. So we'll see how the game unfolds."

Burton, a receiver, and Felder, a cornerback, also are players on the bubble when it comes to making the final roster. Wright is locked in as the No. 3 receiver.

Although the Vikings once again are looking for someone to challenge Sherels, Frazier sounds impressed that Sherels won't let go easily.

"Marcus has a lot of competition for that punt return spot, as well as the nickel cornerback position," Frazier said. "But Marcus has shown that he's a very resilient guy. He seems to find a way. He's battling, like he always does. He's consistent and he's doing well, but we'll see how things will play out over this preseason."

In other news, backup center Joe Berger had to leave camp Sunday night to take care of a personal matter. Frazier said he wasn't sure when Berger will return. With Berger out, rookie free agent Camden Wentz will back up starter John Sullivan.