If its a Traditional Perpetual League you are talking about consider the following from the GAME MANUAL:

Non-Pitchers: Position players (non-pitchers) are limited to 110% of their plate appearances for the corresponding
season. The limit is imposed in a gradual manner. Position players with 150 or more plate appearances in the
corresponding season are unlimited in their use for the first 20% of the season (50% or 25 games in Launch
Leagues). They are limited to 150% of their plate appearances after the first 20% of the season but that percentage
gradually goes down to 110% by the end of the season.

Game 32 corresponds to the 20% mark of the season and this week Trad Leagues played games 31-35. So its POSSIBLE that your team had no additional stolen bases this week but was previously over the usage level which would cause him to be overused. It's also possible that the Hit & Run scenario described by another poster has contributed to the situation.