Robinson has been training with his former club after leaving Raith Rovers and looks set to sign on after McCoist was given the green light by chief executive Graham Wallace.
Steve Simonsen deputised for Bell during Monday's 8-1 Petrofac Training Cup win over Clyde and the former Stoke and Dundee player is likely to keep the gloves for the Scottish Championship visit of Dumbarton, but he will soon have some competition.
McCoist said: "Lee was scheduled to come in and do a bit of training with us anyway but obviously with the injury to Cammy, we are going to have a look at Lee and in an ideal world we will have a wee chat with him. If we can do something, great.
"We have the problem with Cammy being out for two or three weeks, hopefully that will be all it will be, but we need to assess him.
"But we need to protect ourselves with such a specialised position.
"I've had a good chat with Graham and we can bring someone in for that position. We're looking to bring in a competitive goalie, we don't want to bring somebody in just to make up the numbers."
Simonsen is not looking too far ahead as he prepares to utilise his opportunity in the first team.
The 35-year-old, who made three appearances last season, said: "While Cammy is out I will go in there and do my very best and enjoy the little run that I'm going to get.
"I know what's expected performance-wise like every player that comes into the team.
"I'm going to do the very best I can for however long that will be.
"Obviously that's down to myself to see how I perform and get the very best results I can for the fans and the rest of the boys.
"I'm not looking too far ahead, just to the next game against Dumbarton."
Rangers are looking to build on their impressive display against the League Two side, during which Lewis Macleod struck twice in a mature and creative midfield display.
Hat-trick hero Kris Boyd later showered praise on the 20-year-old but McCoist is careful not to heap expectation on a player who missed half of last season through a serious illness.
"First and foremost, it's fantastic to have him back playing after his troubles last year," McCoist said.
"So I wouldn't put any extra pressure on him. But I have to say I would agree with Kris, his level of performance on Monday was terrific, and I don't have any doubt that he will be a big, big player for us in the season ahead."