Brendan Rodgers has stressed that continuity in his Celtic squad is just as important as attracting new players as they bid to reach the group stage of the Champions League.
The Scottish Premiership champions lead hosts Rosenborg 3-1 before the second qualifying round decider in Norway, with AEK Athens to face the winner.
Rodgers is without Dedryck Boyata, Moussa Dembele, Leigh Griffiths, Lewis Morgan and Marvin Compper and the suspended Jozo Simunovic for Wednesday's trip.
"We come with an advantage," Rodgers told BBC Sport. "Like every European game away from home, you've got to defend well, you've got to be strong and we know as we've seen that we can score goals.
"Nowadays, it's always about wanting to get new players and lots of players but I also enjoy the continuity of coaching and seeing players improve and seeing their games continually develop.
"We want to strengthen the squad of course but at this point in time what is most essential is that you build a mentality and a quality to hopefully get through the qualification games."
Celtic have secured the permanent signings of striker Odsonne Edouard and goalkeeper Scott Bain so far this summer.
