Justin Kluivert was sorely missed by RB Leipzig against Liverpool and his injuries are increasingly frustrating head coach Julian Nagelsmann.
Winger Kluivert joined Leipzig from Roma on a season-long loan at the start of the 2020-21 campaign.
However, the 21-year-old - son of former Barcelona striker Patrick - has so far been limited to just three starts and 452 minutes of action in a Leipzig shirt across all competitions.
An ankle issue has provided Kluivert's latest setback, with his last appearance coming in January and his last start before Christmas.
Prior to being named in the line-up against Werder Bremen on December 12, Kluivert had scored in consecutive matches against Bayern Munich and Manchester United - his only goals so far this season.
Nagelsmann was impressed by the Netherlands international's performances in those games and believes his dribbling ability could be a real asset; he leads Leipzig with 5.4 dribbles attempted and 2.6 completed per 90 minutes this term.
But the coach was again without Kluivert as Leipzig lost their Champions League first leg 2-0 against Liverpool on Tuesday, with the German team attempting just 11 dribbles and failing to execute a single fast break.
"At the stage when we played Bayern and Manchester [United], it was the Justin we were hoping for," Nagelsmann said. "After that, he was gone again.
"He just trains very little, I don't see him much in training. That's the problem. He has to become more stable in terms of his body.
"Since he's been here, he's had far too few training sessions and therefore too little impact on the game.
"He basically has skills that would have done us good in the game against Liverpool. They would also do us good in the Bundesliga, like his deep runs and fast dribbling. He's also a goalscorer and has a good finish.
"But he simply has to become more stable. He's a little too injury-prone these days."
Leipzig would reportedly have to pay in excess of €10million to make Kluivert's move permanent.
Nagelsmann is not ruling out the possibility but would like to see more from the player over the coming months, referring again to the standard set in a 3-3 draw with Bayern.
Kluivert scored with his only shot at Allianz Arena, playing 78 minutes after being named in Nagelsmann's starting line-up.
"Obviously, we hope he has an even bigger impact on a successful season, that he stays healthy and that he can train more and get fit again for the games," Nagelsmann added.
"He's welcome to do as well as he did against Bayern Munich.
"In the course of the second half of the season, we will then decide what we do and what he wants to do. And how big his influence was and how it then continues beyond the summer or not, we will decide then."