Barton is on the books of Burnley at the moment, but he appears to be set to leave the Premier League-bound outfit for Scottish giants Rangers.
Barton will arrive in Glasgow over the next 48 hours in order to compete a medical and sign the contract, according to The Scottish Sun.
Gray appears to have confirmed the speculation that Barton is leaving Burnley and has sent a heartfelt message to the Englishman on Twitter.
Sad to see big bro @Joey7Barton go! Learnt alot from him!! Good luck bro— Andre Gray (@AndreGray7) May 23, 2016
Barton scored three goals and created 29 chances in 38 Championship appearances for Burnley this past season.
The Englishman had a pass accuracy of 75% and a shot accuracy of 31%, and won 67 headers, 15 dribbles and 82 tackles.
The former Newcastle midfielder played a key role in Burnley getting automatic promotion to the Premier League.