He is questionable after injuring his knee yesterday in practice.
As per SNY insider Ralph Vacchiano:
was added to the Giants’ injury report this morning by the team, just before they departed for San Francisco. He was officially listed as “questionable” and he did make the trip, but his status will be a game-time decision.
Details of what happened weren’t immediately available, though it appears his knee swelled up this morning, forcing them to list him on the report.