Ramsdale is set to move to Bramall Lane after Bournemouth accepted an offer of £18.5 million for the 22-year-old stopper.
However, manager Chris Wilder has also not ruled out the possibility of trying to re-sign Henderson on a temporary basis after an impressive season on loan during which the England international helped Sheffield United finish ninth in their first back year in the Premier League.
Sources have told ESPN that United are yet to make a decision on Henderson's future and discussions are ongoing.
After a full season in the Premier League with Sheffield United, the 23-year-old is keen to ensure he has regular first team football next term to put himself in a position to compete for England's No.1 spot ahead of the European Championships.
Henderson has already caught the eye of Gareth Southgate and his staff and is in line to get a call up for the September internationals against Iceland and Denmark.
United manager Ole Gunnar Solskjaer has said publicly he will not be able to keep three top-level goalkeepers happy at Old Trafford.