Urbik has started all 13 games this season and played all but seven snaps in Sunday's loss to the Tampa Bay Buccaneers.
"I won't be able to update you during the week, saying 'is he close or is he not close?' I really think it will go all the way until the end. That's how I feel right now," Marrone said. "[His foot] was sore after the game. We thought it would be better and it's not."
If Urbik cannot play, the Bills will start undrafted rookie J.J. Unga at right guard. Unga, who was signed off the Baltimore Ravens' practice squad last month, was active for the first time Sunday. He replaced Urbik on seven snaps, likely for evaluation purposes.
Linebacker Kiko Alonso was limited in Wednesday's practice with a knee injury. Marrone said it was unclear when he got hurt.
"Basically we're just resting him," Marrone said. "I think it's one of things where you can't pinpoint that play. It's just sore. They asked me what I wanted to do, if I wanted to put him out there, go out there and practice. The guy has taken a lot of snaps. I just said 'You know what, let's limit him.'"
Here's a look at Wednesday's full practice report:
DID NOT PARTICIPATE
DT Kyle Williams (Achilles)
OL Kraig Urbik (foot)
LB Kiko Alonso (knee)
CB Brandon Smith (ankle)
S Jonathan Meeks (ankle)