Vikings head coach Mike Zimmer expects center John Sullivan and guard Vladimir Ducasse will be fine for Sunday's road game against the Buccaneers.

Sullivan passed has passed his first concussion protocol test, while Ducasse walked around the locker room on Wednesday without a brace. Ducasse said his knee was feeling better after falling on it during the first quarter on the same play Sullivan left due to a concussion against the Bills.

"I don't know how, but I just fell and fell on top of the knee," Ducasse said. "That was about it. I went to get up, and I couldn't put weight on my foot. But I'm fine."

Neither returned to the game with Joe Berger filling in at center and Mike Harris at right guard in the 17-16 loss on Sunday, but Zimmer was optimistic about the two biggest injury concerns this week.

As for his own health, Zimmer had his kidney stones removed on Tuesday. He missed practice on Friday due to a minor procedure but still coached with kidney stones on Sunday. It was about as painful as it sounds, but the health issue has finally been resolved.

"[Tuesday] wasn't pleasant at all," Zimmer said. "[Head Athletic Trainer] Eric Sugarman was talking to the team today, and I told him to get the video of the procedure that I had done to show the team. I think there would've been some [players] throwing up or something."