Isak's Fitness Shocks Slot in Liverpool Debut Against Atlético Madrid

LIVERPOOL, England -- Liverpool head coach Arne Slot has admitted he was surprised by the fitness of striker Alexander Isak during his debut against Atlético Madrid.

The Sweden international played 58 minutes of Liverpool's 3-2 win before being replaced by fellow summer signing Hugo Ekitike. Isak joined the Premier League champions from Newcastle United on transfer deadline day for a British-record £125 million ($171m) and is still working his way up to full fitness following a disrupted preseason.

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"In the 60 minutes he played he seemed to be quite fit to me," Slot told TNT Sports. "It wasn't as if after 10 minutes he was already very tired. He could play at this level quite well after one or two weeks of team sessions.

"So that was the thing and he can play football and that he's a joy to watch and that is not a surprise to me. He was fitter than I expected but the fans can't get their hopes too high. We play three times a week and that's a bit too much for him still.

"We have two great number nines and we're going to use both of them throughout their career here."

Liverpool snatched the victory on Wednesday night with a late header from captain Virgil van Dijk, having surrendered a two-goal lead for the third time this season.

Reflecting on his team's performance, Slot said: "If you want to beat a team like Atlético, which has an unbelievable mentality, you have to beat them with their weapon as well and that is mentality and that is what we showed again today that we can beat them with mentality.

"I think we should've made it easier for ourselves -- at 2-0 first half we got more than a few chances to make a third. At 2-1 second half we hit the post, we were so close a few times and if the margin is only one goal something can always happen and it happened.

"A little bit deflection I'm not sure but second ball went in, but again we showed mentality because in that 10 minutes that still had to be played we were pushing, pushing, pushing and we scored a set-piece goal."