Fraser Forster was in the stands, as Celtic seen off AIK in the first leg, 2-0.
Forster has struggled to get in the Southampton team of late, but now has a chance to get some first team football under his belt.
Lennon told the BBC : “He gave me a hug in the doctor’s room, I think I came up to about his navel – he looks like he’s got bigger!
“We’re delighted, it’s a crucial part of the squad. Bain is out so we had to get another one in.
“We’ve got two outstandingly fit goalkeepers so it’s an important department and I’m glad we’ve strengthened it.”
When asked if he would replace Bain or Gordon he said: “Mind your own business!”
And Lennon added: “I’m very happy, it was a great performance from everyone.
“I’m happy with the clean sheet and we’ve got goals in us. My only observation is we didn’t score more.
“We played some brilliant combination play and we upped the tempo second half and scored two great goals.
“We had to be patient, they defended well at times.
“But we said at half-time ‘just a little bit more!’. The 10 or 15 minutes after half time were going to be important and of course we get the breakthrough and had control after that.
“Off the back of what’s been a difficult week for the players they’ve come up trumps again.”