The midfielder, on loan from Brighton, was on the end of a nasty aerial challenge by the Millers' Jason Taylor which required lengthy on-pitch treatment and subsequently 11 minutes of injury time.
But Gills boss Martin Allen has allayed any fears of serious injury and it is hoped Vincelot will return to training later this week.
"I spoke to Romain Vincelot on Sunday afternoon and apart from a headache and a stiff neck he is feeling fine," Allen told the club's official website. "He will now be assessed by our doctor, Harbinda Singh, and we will review if he can start training on Thursday.
"Our physio Gary Hemens did a remarkable job to clear his airways and, on behalf of everyone at Gillingham football club, I must thank the medical team at Rotherham Football Club for their prompt, swift excellence in helping and supporting Gary and Romain."