Bain, who joined Celtic on loan from Dundee in the January transfer window, made his debut for the Hoops in the Old Firm derby against Rangers at Ibrox at the weekend.
Although the 26-year-old goalkeeper conceded two goals, the overall performance of the former Aberdeen prospect was impressive, as the Hoops won the Scottish Premiership game 3-2 on Sunday afternoon.
Falkirk manager Hartley worked with Bain at Alloa Athletic and Dundee, and he has praised the Celtic goalkeeper with whom he played at Aberdeen as well.
Hartley told The Scottish Sun about Bain: “Scott has always been excellent with the ball at his feet, and that’s important in the modern game.
“We used to play little training games and he would play outfield sometimes. He has good ability.”
Key factor in Celtic future
Celtic manager Brendan Rodgers likes his goalkeepers to play with the ball at their feet and build attack from the back.
Hartley’s comments about Bain being good with the ball at his feet could be a reason why Rodgers signed the 26-year-old on loan in the January transfer window.
It could also be a key factor in Celtic signing the goalkeeper on a permanent contract in the summer of 2018, with The Scottish Sun claiming that the Glasgow giants are interested in keeping him at Celtic Park for next season.