Center Stefen Wisniewski hasn’t practiced since suffering a calf injury in the preseason opener against Dallas, but Raiders coach Dennis Allen said Monday he’s not leaning toward keeping an extra center on his 53-man roster.

“I don’t think that will affect our total number because I don’t anticipate this being something that would keep him out for any extended period of time,” Allen said. “We’ll know here within seven days, 10 days, what his outlook is for the opening of the season.”

Alex Parsons has started the past two games and played well. If the Raiders don’t carry another true center on the final roster, right guard Mike Brisiel would be the likely emergency center after Parsons, Allen said.

“I’ve been backup center for the past few years in Houston,” Brisiel said. “Luckily nothing happened. I’ve played some games. You go into games, you’re going to dress usually seven guys. So you got to have guys that do both. I knew that, coming in. It’s not something we plan on happening, but if it does, we shouldn’t miss a beat.”

Brisiel played tackle in college, but he played a season at center in NFL Europe and has taken some snaps at center during training camp with the Raiders.

“I understand our blocking schemes and everything,” Brisiel said. “I hope it wouldn’t come to that, but you’ve got to be prepared for everything.”

Serious business: The Raiders went through a full practice Monday at team headquarters in Alameda for the first time since breaking camp in Napa. There were fewer players on the field after Monday’s mandatory roster cut to 75, and a different feeling on the field.

“Every time you change the surroundings, people realize there’s a little something different,” Allen said. “Getting back here, it’s kind of, we’re getting close. I think everybody feels the sense that we’re getting close to the opening day of the season.”

Rookie guard Tony Bergstrom, a third-round pick, said it’s sobering to see players get cut.

“It’s crazy. It just makes you want to go that much harder in practice because you never know,” Bergstrom said. “It kind of makes you realize that this is a business and it’s not necessarily a nice business all the time, either. So it makes you appreciate being here as long as you have and you just want to hold on that much longer.”

Extra points: TE Richard Gordon missed practice again with bruised ribs that he suffered at Arizona while making a tackle after a Cardinals interception. “Working on them,” Gordon said. “I know I’ll be back soon.” … OLB Aaron Curry (knees) remained on the preseason PUP list, and Allen said he won’t decide whether to put him on the regular-season PUP list until Fridays’ deadline. If he goes on that list, he’ll have to miss the first six weeks before being eligible to return. … DT Richard Seymour missed practice again to rest his sore knees. He’ll be a game-time decision Thursday, Allen said. “It’s the same issues he’s been dealing with for awhile now. It’s nothing more than some tendonitis, and it’s something that you’re going to have to manage. When you get into the regular-season games, you play through some of that stuff.” … No. 2 QB Matt Leinart, a left-hander who missed last week’s game with a lacerated right index finger, was full-go in practice and is expected to play at Seattle, Allen said. … K Sebastian Janikowski (groin) did some jogging and stretching but no kicking during the 30-minute media window at practice. … WR Jacoby Ford (foot), WR Denarius Moore (hamstring), CB Pat Lee (back) and OT Zach Hurd (head) also missed practice.

Follow Raiders reporter Eric Gilmore on Twitter @CBSSportsNFLOAK.