Celtic manager Neil Lennon has urged his players against ruing a "wasted opportunity" as they head to Benfica on Tuesday night looking to book their place in the knockout phase of the Champions League.
An impressive 2-1 home win over Barcelona in their last Group G game has provided Celtic with a chance of reaching the next round of Europe's most prestigious competition, with a win in Lisbon enough to seal their passage.
Lennon, though, is wary of his side's opponents, after they were held of a 0-0 draw in their first meeting at Parkhead in September.
He said on UEFA's official website: "The game against Barcelona was good, but there are two matches to go. I played here in 2007 and I know how it is. We have to be defensively at our best and attack when we can. If we fail to qualify now it would be a wasted opportunity. But the job is not yet done.
"At home against Benfica, it was a bit of a tactical battle. Nemanja Matic has been very important for Benfica. The full-backs and centre-backs too. Melgarejo is fantastic. I know Lima well from the time we faced Braga.
"Also Oscar Cardozo is a terrific striker, but Benfica are not just about individuals, they are strong as a team and don't lose their identity when the coach changes some players. Luisão is very experienced; I played against him. He's always on his game and we know how important he is for Benfica.
"Celtic won the 1967 European Cup here. We'll train at the Estadio Nacional so the players can experience part of the club's history."