McCoist is delighted to have the talented 19-year-old available for selection once again after his debilitating illness, but as he prepared for a pre-season friendly with Brora Rangers tomorrow, he insisted he would handle the Scotland Under-21 player with care.
The Rangers manager said: "Lewis maintained a great level of strength throughout his time out. But we're not putting any pressure on him at all. I still think it will take him a bit of time to come back because there will be a confidence issue there as well.
"Lewis was nothing like the finished article when he got this viral problem so he's still got a lot of developing to do as a player. But it's just brilliant to have him back. He's one of those players who will do something in a game or do something in a training session and the boys will have a wee look at each other and say 'He's done something special there'.
"It's a little bit early to see how up-to-speed he is. He's naturally fit. But there's a really thin line. We need to look after him, but at the same time we don't want to mollycoddle him. The most important thing is that he's been given the all-clear to take part in training and play games again."
Another of Rangers' talented young players, Calum Gallagher, believes he and his peers will get the chance to shine at Ibrox - if they can prove they are good enough to feature in the first team.
Gallagher started the club's first pre-season game against Buckie Thistle on Thursday night and scored two goals in a 3-0 victory. The 19-year-old broke through in the second half of last season and looks in line to feature regularly in McCoist's team.
Rangers, though, have come in for criticism during the summer for their youth policy after promising midfielder Charlie Telfer turned down the offer of a new contract. The 18-year-old was reportedly disappointed by his lack of first-team action at Rangers and opted to join Dundee United instead.
The recent signings of Kris Boyd and Kenny Miller, who are 30 and 34 respectively, has added to a sense among some supporters that McCoist does not allow young players to flourish. However, Gallagher dismissed those claims, saying: "The manager played a lot of the young players the other night in our pre-season friendly against Buckie and I think that goes to show the mentality he has.
"If you are good enough it is not an issue how old you are. You just need to get your head down, work as hard as you can and prove your worth. There was a lot of attention on Charlie Telfer's move. I think that maybe resulted in some criticism about the club and their development of youth players."
Gallagher was set up for his second goal at Victoria Park by Barrie McKay and he predicted the Rangers winger will thrive in the new season. McKay was loaned out to Morton last season and he appears to have benefited from his time in the SPFL Championship.
Gallagher added: "Barrie was excellent against Buckie. I was with him a couple of times over the summer and he has kept himself really fit. I think that by playing in the Championship he will know what to expect this year. He will relish it. He is that kind of player, he just loves playing football."