Georgios Samaras and Nir Biton are both struggling with viruses ahead of Celtic's Scottish Premiership clash with Motherwell at Parkhead on Saturday.
Midfielder Joe Ledley remains out with a groin complaint while wideman Derk Boerrigter had an injection in his troublesome ankle, with Lennon hoping he will return after the international break.
The Hoops received a boost ahead of the match when defender Efe Ambrose signed a new four-year dea.
The Nigeria international signed from Israeli side FC Ashdod on transfer deadline day in August last year and his new contract will keep him with the Scottish champions until 2017.
Ambrose was a central figure as Neil Lennon's men celebrated a league and cup double during his first season in Glasgow and he also helped the Hoops reach the last 16 of the Champions League.
He said: ''I have thoroughly enjoyed my time at Celtic so far and I am absolutely delighted to extend my stay at such a fantastic club.''
James McFadden faces a late fitness test for Motherwell..
The striker went off at half-time against Ross County last weekend with a tight hamstring.
Manager Stuart McCall is set to be a bit more cautious despite beating Celtic in their last two matches, both at Fir Park, with a bold attacking formation in the second game especially.
''I think it is a different story,'' he said. ''Even in European ties, I always think you have to try to take your chance at home.
''Going away from home, with the size of the park, you do think a bit differently. Not in a negative way.
''At home I think you should always try to win the game no matter who you're playing. Not that we are not trying to win - but you do look at it differently.''