Adam Lallana is a doubt for Liverpool's game with Tottenham Hotspur on Sunday as the club continue to carefully manage the midfielder's fitness.
Lallana has missed Liverpool's last two matches with a muscular injury and has made just seven appearances this season, having sustained a long-term thigh injury in preseason.
Jurgen Klopp says Liverpool must be patient with the England international as he works his way back to full fitness.
"It's really unlucky. It was a really serious injury in the summer. Because of Adam's quality and attitude in training, it looks immediately like we can put him in, [but] physical-wise he's not fit," Klopp said.
"The two things that happened after his big injury were in the 10 or 15 minutes after he came on. From nil to 100 in a second, and that's maybe what caused the problem.
"We really tried to be sensible with it, to do the right thing. But it didn't work, twice. It's really not a big thing, three games is like not being injured.
"He's maybe available for Tottenham, and if not then he'll have missed three games. That's really OK but of course it's not cool. The body needs to adapt again to the intensity."
Klopp added later on Friday at his prematch news conference: "Adam trains today completely normal. In an ideal world, then he should not be involved for the weekend. How we all know, there's really different stages of being fit. Being able to train and then being match-fit is different.
"Adam was not out too long, had the longest preseason of all of us with the injury he had. It will not be long.
"If nobody will be injured or whatever, then it's better for Adam that he can train in the next 10 days or round about until the Southampton game and then he should be ready then."