Tramaine Brock has the experience at nickel the Vikings need

Mike Zimmer isn't sure when Tramaine Brock will get up to speed, both mentally and physically, but he says he's sure the 29-year-old cornerback could help the Vikings in the slot if necessary.

"He's played nickel a lot," Zimmer said Tuesday. "Played nickel in Seattle the whole time he was there and he played [outside] corner in San Francisco."

The Vikings sent a seventh-round pick to Seattle last week for Brock, who did get a chance in 2015 to defend the slot for the 49ers when starter Jimmie Ward went down. Brock is currently nursing a groin injury, according to Zimmer, preventing any immediate impact.

"I thought that his cover skills were good in the things that he had done in the last year," Zimmer said, "and his ability to do the things that we do defensively."

Brock's role could be as reserve or replacement, whenever he gets settled. Mackensie Alexander is expected to be the Vikings nickel cornerback despite showing this preseason how far he has to grow.

And Brock could still face NFL discipline. He was released by the 49ers in April a day after his arrest on suspicion of domestic violence. Brock's case was dismissed by prosecutors in August, but "the matter remains under review" by the NFL, league spokesperson Brian McCarthy said in an e-mail to the Star Tribune.

"I think that we've done our due diligence," Zimmer said.

A 2015 fourth-round pick, Bell is the third tight end on the Vikings roster, which means he could be active on game days. At 6-foot-6 and 252 pounds, he could help the Vikings on blocking units just as he did for the 49ers this preseason at U.S. Bank Stadium.

"He's more of an all-around guy," Zimmer said. "I think he'll help us in all phases. He played some special teams."

The Saints traded 1,000-yard receiver Brandin Cooks to the Patriots. But Drew Brees has another in second-year standout Michael Thomas, the second-round pick who gained 1,137 receiving yards as a rookie. Vikings cornerback Xavier Rhodes said their connection is apparent on film.

"Him and Drew have great communication," Rhodes said. "Drew knows once the guy's on top, him and Michael Thomas are going to go back shoulder. We just have to play tight coverage."

The Vikings were nearly at full strength to start the first week of the 2017 regular season. Defensive end Brian Robison (leg) and guard Danny Isidora (undisclosed) were the only two held back.

The Vikings will issue the first injury report after Thursday's practice.

Former Vikings guard Alex Boone returns to the NFC West, where he spent six seasons with San Francisco, after agreeing to terms with the Cardinals on Tuesday, according to his agency.