Crystal Palace manager Alan Pardew has told Wilfried Zaha that he most improve his concentration.
The winger, who has completed a full 90 minutes once this season, was substituted at half time in Palace's 1-0 defeat to Tottenham Hotspur at White Hart Lane on Sunday.
Pardew has suggested that the 22-year-old could go on to be a great player if he increases his work rate.
"The issue with Wilf is that he's a fabulous footballer. I'm trying to get him to understand that every moment in every game is very important," Pardew told Reuters.
"It's about concentration, about having that same desire to defend and attack, movement and everything that a top player produces. Unfortunately I didn't think he did that. He had 45 minutes to show me he was up to speed on those areas and he wasn't. He needs to take away a lesson.
"He's perhaps unlucky to be taken off because there were one or two others that were probably just below the level, but he was probably worst of the pack."
Zaha has played six Premier League games for Palace so far this term.