Defender Thomas Rogne (ankle), skipper Scott Brown (groin), striker Georgios Samaras (thigh) and midfielder Kris Commons (ankle) all missed Saturday's Clydesdale Bank Premier League win at Inverness. Celtic are 2-0 up from the first leg in Sweden and are favourites to go through to the group stages for the first time since 2008-09.
Lennon said: "We still have a few nagging doubts regarding the boys we left out at the weekend so we will see how they are tomorrow."
He added: "Thomas has an ankle problem, Kris has an ongoing ankle problem and Scott (is a doubt) with a sore groin.
"Some might not be fit to play, some might, so we will just have to gauge that tomorrow. But apart from that, we came through the game at the weekend injury-free so we will have a decent-sized squad to pick from."
Lennon confirmed striker Mo Bangura has returned to AIK Stockholm on loan after his £2.2million move from the Swedish club last year proved unsuccessful.
The Parkhead manager said: "He is away back to Stockholm for a year's loan. He is still our player but he needs to play some football and get himself going again.
"Possibly the expectation of the price tag weighs a little bit on younger players at times.
"We know he is a talent but has been hampered by injuries. He is fit now and we think it is a good time for him to go and play football and come back here a better player."
Lennon admitted the club had expressed an interest in Auxerre defender Willy Boly and Rosenborg midfielder Markus Henriksen, but denied making a move for former Liverpool and Manchester United striker Michael Owen.
Source: PA
Source: PA