Liverpool manager Arne Slot has criticised pundits who "favour other clubs" for their comments over the club's summer spending as he prepares to give a debut to Alexander Isak.

The deadline day signing of Sweden striker Isak from Newcastle for a British record fee of £125m took Liverpool's spending to £450m on eight players.

Isak is set to make his first appearance for the Reds in their Champions League opener against Atletico Madrid at Anfield on Wednesday.

At his pre-match news conference, Slot pointed out that Liverpool's unprecedented spending was offset by more than £250m recouped in sales, having spent just £10m the previous summer.

"There is so much focus on our new signings, especially from pundits who favour some other clubs in the country that cannot stop talking about £450m," Slot said.

"I repeat, £450m, £450m! But they forget about [nearly] £300m that we have sold [players] for. So, yes, if we want to strengthen the squad, we need to spend that much money."

Slot felt Liverpool "did great business", given all eight of their signings are aged 25 or under, and the club "should get praise" for the strategy it has adopted.

"I think it is only a compliment that people tell everyone we have spent so much because that tells you the players we brought in are seen as very good players," explained the Dutchman.

"Some other teams prefer to bring in 27-year-olds because they are ready, but we think we have brought in players who are 21, 22 [and] who are ready.

"I think all the money we have spent we generated ourselves by selling, and by winning the league after we didn't buy anyone at all."

Isak did not feature in Liverpool's 1-0 win at Burnley on Sunday - the first match since he joined the Reds - because he is still short of match fitness.

The 25-year-old trained alone at former club Newcastle, in a bid to force through his switch to Anfield, and needs extra work to get up to speed after missing pre-season.

Isak's only appearance this season came for Sweden in an 18-minute cameo from the bench in a 2-0 defeat by Kosovo last week.

Slot said he is "100% sure" Isak will not play 90 minutes against Atletico but indicated he will play a part against the La Liga side.

"He [Isak] is part of the squad, so it's already a Champions League game to look forward to, but if people look forward to his playing time, that could mean that could happen tomorrow as well," Slot added.

"So the moment he is fit, match fit, [he] can play 90, and then the next step is playing three times in a week 90 minutes.

"And that is what he has to do; scoring goals and doing special things in attack is something he will 100% do. The main challenge he has is to become so fit that he's first of all ready to do what he did last season."