In the first leg Porto won 3-0 away on Stade Louis and they controlled the game from the beginning till the end 8-1 shots on goal.
At this moment Porto is situated on the 2nd position and they need to win in order to be sure they will qualify from group stage. They will be able to qualify, even if they draw or lose, if Leipzig will do the same against group winners Besiktas. (Porto has the head to head advantage Porto - Leipzig 3-1 / Leipzig -Porto 3-2)
Regarding injuries :
Porto's coach Conceicao has full squad at his disposal.
Monaco's coach Jardim has several injured players , most important will be the absence of Tielemans Y. and Jovetic S.
All the stats are in Porto's favor , only Falcao's pride could produce the surprise here.