So far, so good. That's the message Vikings coach Leslie Frazier sent today when it came to the health of the team's top three cornerbacks.

That's a good thing considering the Vikings travel to San Diego on Sunday to face quarterback Philip Rivers, a standout receiving corps featuring Vincent Jackson and last year's No. 1-ranked offense.

Chris Cook, who was slowed by a hamstring injury in the preseason, practiced on Monday. If he doesn't suffer a setback this week, he'll be the nickel back.

"Hopefully he puts together another good day today," Frazier said. "But so far, so good."

The other concern is the amount of plays starting right cornerback Cedric Griffin will be able to take. He's coming off his second torn ACL in as many seasons and has only played limited snaps in two preseason games.

"All indications are he's going to be fine," Frazier said. "But still he's had limited exposure in the preseason for obvious reasons, coming off a second ACL surgery in a little over a year. So we're all anxious to see how he performs. We'll probably have too monitor how much he's on the field and how things are going. We're excited and we need to see how he's going to do on Sunday."

If Griffin has to be taken off the field, Cook has to play more, which brings Marcus Sherels or Asher Allen on the field in obvious passing situations. Allen hasn't played or practiced since the preseason opener. He has a toe injury, but is practicing this week, Frazier said on Monday.

Frazier was asked if he'll dress more defensive backs because of the Chargers' passing offense. He said it's not how many DBs that's important, it's WHICH DBs he has available. Clearly, for the team to be more competitive against the Chargers, the Vikings need Antoine Winfield, Cook and Griffin at full strength. The safeties will be Husain Abdullah and Jamarca Sanford to start. Tyrell Johnson could rotate at strong safety with Sanford, Frazier said.

"Their offense doesn't make you have to have a lot of defensive backs [active]," Frazier said. "It's the way they utilize their personnel. You just want to make sure you have the right people on the field when it comes to your secondary because you're going to be spread out and you're going to be in matchup situations where you're really going to need to make plays. I think we got the right guys to make the plays. It's not necessarily the right guys. It's having the right guys."

Even at full strength, the Vikings' secondary will be stressed by the Chargers' attack on Sunday.

"[The Chargers] are a challenge for any defense, let alone coming off what we're coming off from a health standpoint," Frazier said. "Terrific receivers, terrific quarterback. No. 1 offense from a year ago. So it will be a big challenge for us. We'll find out where we are early on."

Other highlights today:

  • Jim Marshall spoke to the team this morning. "He had instant credibility with out players," Frazier said.
  • Frazier said the 53-man roster is "a fluid situation." "Things could happen," he said. "We're always trying to better our football team. It'll be that way throughout the year, which will be good for our team." Don't expect any changes between now and Sunday's opener.
  • Frazier said Marcus Sherels has won the punt return job. Veteran Greg Camarillo is available if there's a problem with Sherels, but Sherels will start the season as the No. 1 punt returner.
  • The team has not decided whether to use Percy Harvin on kickoff returns. They're still evaluating the new 35-yard-line rule and whether it makes sense to have Harvin return kicks.
  • The team added DB Domonique Johnson and LB Tyrone McKenzie to the practice squad. FB Matt Asiata and DL Cedric McKinley were released from the practice squad.
  • Everson Griffen was back working with the defensive line in the portion of practice that was open to the media. Today. He was switched to linebacker last week.
  • The team wore helmets and shells in practice today, so there wasn't much contact expected.