Adeyemi was a stand out player for Rotherham during a miserable campaign at the bottom of the Championship, scoring six times in 29 matches.
Millers face competition from Championship pair Ipswich Town and Norwich City over his signature but boss Paul Warne was hopeful of securing his services.
Warne has also confirmed Rotherham have offered fresh terms to Joe Mattock, Richie Smallwood and Richard Wood, whilst Jonson Clarke-Harris agreed a new one-year deal on Tuesday.
However, former player of the year Lee Camp was among a list of eight players released by the relegated outfit.
Camp, who made 59 appearances for the Millers, won the player of the season award after helping the club remain in the Championship in the 2015/16 season.
Warme has also released Stephen Kelly, Kelvin Wilson, Joel Ekstrand, Tom Thorpe and Chris Dawson while young professionals Fabian Bailey and Tom Rose have not had their deals renewed.
Loan players Carlton Morris and Scott Allan will also return to their parent clubs following the completion of their loan deals.
Warne said: “We wish all the lads who are leaving the very best for the future, but I would particularly like to acknowledge the contribution of both Lee Camp and Stephen Kelly.
“Both were key figures in keeping the Club in The Championship during the 2015/16 season, and Campy deservedly picked up the player of the year award for his efforts.
“They are both great lads and served the Club with distinction during their time here.
“I wish all the lads every success with their next move.”
The Millers finished bottom of the pile in the second tier after winning just five matches and accumulating a points haul of 23.
Warne became Rotherham's third manager of the campaign after taking over from Kenny Jackett and has been backed to lead the South Yorkshire club in League One next season.