Jurgen Klopp hailed the resurgence of Adam Lallana as he saluted the Liverpool midfielder's “incredible” attitude.
The England international has put an injury-plagued 18 months behind him to play an important part in the Reds' Premier League title challenge in recent weeks.
Lallana has started back-to-back league matches for the first time since May 2017 and Klopp described him as "a joy to watch" ahead of Sunday's visit of Tottenham.
"If a player is injured it is never good, when they come back, you see the smiles," Klopp said.
"Yesterday Joe Gomez was like Christmas, birthday, everything in his face. You could see it, brilliant.
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"When there are setbacks you are like 'come on, there will be better times', but the boys have to go through a lot of darker days pretty much alone with their families and friends. You cannot change it. There is no alternative to rehab.
"But a player with the ability and skills of Adam Lallana is a pure joy to watch when the fitness level is increasing and he is back on the pitch.
"It is clicking for him again. His attitude was always incredible so why should I doubt him? Only the football world outside make a player old too early. I don't think like that."
Lallana, who turns 31 in May, forced his way back into Klopp's starting line up with his efforts on the training field at Melwood. The manager believes it shows those other players on the fringes what can be achieved if they light up sessions in similar fashion.
"Adam is in a wonderful age group and when he is fit he is a fantastic player. That is the only thing I was waiting for. You cannot force that," Klopp added.
"You can only appreciate it when he is back and we showed that against Burnley. We had a full week to train for that game and Adam was the stand-out player in training that week so go for it.
"Every player has to know that we really watch and judge training. And if possible we show that we saw it. In that case it was important, not just for Adam but for the rest of the squad as well."
