Arne Slot revealed after the goalless draw against Leeds that Florian Wirtz could only train once in the lead up to Leeds‘ visit on Thursday evening.Wirtz was named in the starting lineup for the seventh game in the last eight on New Year’s Day, with Slot opting to keep the German on the left of the attack.He showed flashes of breaking the game open and had an opportunity to score himself, but his night ended after 66 minutes as Liverpool sought a breakthrough.It was not the No. 7’s best performance and, after the match, Slot revealed that Wirtz had only been able to train once this week due to a hamstring complaint.“We have to wait and see how they come out of the game,” Slot told BBC Sport when asked about his selection for Sunday. “Florian, for example, only trained once this week because he felt his hamstring at the start of the week.“That’s why I didn’t want to take the risk of playing him too long with all the games coming up, this is what we have to manage.“It’s the situation we have to accept and where we are in.”Wirtz has played 579 of the last 720 minutes across all competitions and has shown signs of fatigue and cramp, notably clutching his hamstring late in the win at Tottenham.Cody Gakpo‘s return from injury could prompt a change at Fulham on Sunday, with the Dutchman in contention to start after coming off the bench in the last two games after his injury absence.It might not prove the popular decision, but Liverpool have eight games in the remaining 30 days in January and cannot afford more selection constraints with new injuries.After making three changes against Leeds, Slot did say he was “not too sure if we do this in the next game,” as he had four players 19 years or younger with “hardly any playing time in the league” on his bench.