Celtic’s 2-1 loss at Kilmarnock last weekend has thrown the title race wide open in Scotland this season.
Rangers are now just five points behind Celtic in the league table having played a game fewer and the two sides are set to face each other at Parkhead on 30th December.
Bell insisted that Rangers have improved under Philippe Clement but stressed that they still need to get much better in order to win the Scottish Premiership.
However, the former goalkeeper stressed the importance of the January window and believes that the team who recruit better next month are likely to win the league this season.
Bell said on Clyde 1’s Superscoreboard: “Rangers are getting better under Clement but I still think there is a long way to go.
“I still think they need to get even better.
“What I would say is that it’s a massive January for both clubs.
“I think the recruitment in January will decide who wins the title this season.”
Rangers are expected to back Clement in January, while Celtic will look to make sure Brendan Rodgers gets the players he wants.
