The Blades have given no indication as to why the 24-year-old has been suspended
Former Everton forward Baxter has made 28 appearances for Nigel Adkins' side this season, scoring seven goals.
A brief statement on the club's official website read: "Procedures are being followed and no further comment will be made until the completion of these actions."
Baxter has been suspended by United before, in May 2015, for failing a drugs test
He was handed a five-month ban, three of them suspended, by the Football Association but was able to begin playing again before the start of this season.
During his time at Everton, Baxter was released without charge after being arrested on suspicion of possession of cannabis with intent to supply back in 2009.
Source : PA
Source: PA