Ryan Jack, left, will be out of contract with Aberdeen this summer. Craig Watson/PA Wire

Major League Soccer side Columbus Crew SC are closing in on a deal for Aberdeen midfielder Ryan Jack, sources close to the player have told ESPN FC.

Aberdeen captain Jack will become a free agent this summer as his contract at Pittodrie expires.

The Scottish club had been hoping to secure the midfielder on a new deal, but an offer from Columbus could convince Jack to move to America. The MLS club declined to comment.

Jack has come through the ranks at Aberdeen and has established himself as one of the best players in the Scottish Premiership.

Rangers have been credited with an interest in Jack, but it appears Columbus have won the race for Jack's signature on a free transfer.

Crew SC have enjoyed a good start to the MLS season, currently sitting in second place in the Eastern Conference.

The MLS transfer window closes on May 8, but Columbus can sign a free transfer like Jack past the close of the window as long as he is out of contract.