Barton is on the books of Premier League-bound Burnley at the moment, but his current contract with the Clarets runs out at the end of next month.
Rangers manager Mark Warburton recently told BBC Sport that he wants to sign the former Newcastle United midfielder on a free contract in the summer transfer window.
Former Rangers star Johnstone believes that the 33-year-old midfielder would prove to be a good addition to the current Gers’ squad.
“Joey may be 33 but there is no doubt he is still a very good player,” the Rangers legend wrote in The Glasgow Evening Times. “He was instrumental for Burnley as they won promotion back to the Premier League and he was named in the Championship Team of the Year. There is no doubt that he would revel in Scottish football if he did sign for Rangers.”
Barton was one of the best players in the Championship this past season, and proved that he is still a very good footballer.
The Englishman is good enough to play in the Premier League, but perhaps he should look to join Rangers in the summer.
Rangers will compete with Old Firm rivals Celtic in the Scottish Premiership next season, and that should be a great incentive for someone like Barton.