MIKAEL LUSTIG must prove his fitness today - or rookie teenager Darnell Fisher could find himself fired into tonight's Champions League clash with Ajax.

Neil Lennon considered the 19-year-old too raw to come into contention for this vital game - until Fisher made a stunning first competitive start in Saturday's draw with Hibs.

Lustig sat that game out after the excess piece of bone in his hip caused the joint to lock while on international duty.

With Emilio Izaguirre back after illness, and Kris Commons definitely joining Derk Boerrigter and Adam Matthews in being ruled out, Fisher is very much in Lennon's thoughts.

The manager said: "We'll assess Mikael today, but we're pretty hopeful he'll be fit. I'd not have any problem putting Darnell in after his performance on Saturday.

"For a debut it was very composed and mature. That gives us a lot of confidence in him and the young player a lot of confidence in himself."

After pulling a hamstring at Easter Road, Commons is already facing a race to be fit for the game in Amsterdam in a fortnight.

"Kris has been for a scan and we're waiting on confirmation, but he is feeling a lot better," reported Lennon.

"We're hoping it's not as bad as a tear. He's out tonight, but may make the game in Amsterdam."

Lennon also confirmed James Forrest suffered no reaction to his prolonged run out at the weekend as he continues to regain strength after being floored by a virus which the manager admitted they feared might have been meningitis.

He said: "At first we thought it could have been meningitis. But, thankfully, it wasn't as serious as that. We haven't really got to the bottom of what it was.

"It scared us all, really. You always knew he was going to recover, and he has recovered well."

Lennon was in Milan for the opening group stage game when Forrest was hospitalised with his mystery condition, and he recalled: "When you hear something like that (suspected meningitis), you just say, 'Wow', because it just came out of the blue.

"We had seen him on the Friday, when he came back from Macedonia (with Scotland). He wasn't fit to play at the weekend, but we thought he's be okay to travel to Milan. Obviously, he wasn't. Thankfully, he's over it now and is looking a lot healthier again."