The 19-year-old was injured during a training session with the Blades and has now returned to Melwood where his injury will be assessed further.
The full extent of the injury is not yet known and it is unclear how long Woodburn will be sidelined for.
Woodburn, whose last Blades' appearance was in early November, reportedly attended Liverpool's win against Manchester United on crutches and wearing a protective boot on his left foot.
Woodburn has struggled for regular game-time since joining the Blades on a season-long loan in August.
The Wales international has made just two starts in all competitions this season, appearing as a substitute in six further games.