Benfica boss Rui Vitoria says his players are treating Tuesday's Champions League crunch match with Napoli like the final.
The teams are tied at the top of Group B but, having lost in Naples on matchday two, Benfica need to win to be certain of qualifying for the knockout stages.
Besiktas, a point behind in third, face Dynamo Kiev as they attempt to pounce on whichever team slips up.
"The players are ready, they know the importance of this game," Vitoria said at the pre-match press conference.
Napoli coach Maurizio Sarri says his team are in Portugal to beat Benfica on Tuesday night, even if a draw would be enough to take them through to the knockout stages of the Champions League.
The Azzurri have the luxury of two results at their disposal to reach the last 16 of Europe's elite club competition, but only one result would guarantee them top spot in the group. They would even go through by losing if Besiktas fail to win their game against Dynamo Kiev, but Sarri says his team must only...