Mauricio Pochettino says Dele Alli's tendency to go to ground too easily "doesn't help him, doesn't help the team and doesn't help football".
Tottenham cruised to a 4-0 win over Huddersfield Town thanks in part to a double from Harry Kane, who took his tally for September to 13, while Ben Davies and Moussa Sissoko were also on target.
Alli hit the post in the first half but the second saw him receive a yellow card for simulation after going down under minimal contact from Huddersfield goalkeeper Jonas Lossl.
Pochettino claims he did not see the incident in question but, in the week Alli was banned for one international match for an offensive gesture during England's World Cup qualifer with Slovakia, Pochettino has called on him to change his ways.
"I didn't see. It's so difficult for me from my position. But if it was like this he needs to learn. He must learn," Pochettino told a media conference.
"This type of action doesn't help him, doesn't help the team and doesn't help football.
"We are talking in the last few years about fair play. I think he is improving a lot and learning but still he must learn."
Huddersfield boss David Wagner said of his side's showing: "They have top quality in the final third and deserved to win, but we made it too easy for them to score.
"Maybe the scoreline was a bit high given the effort of my players, but it is a deserved result.
"We had our moments in attack, but we made easy mistakes in our final third against a real top quality team. We wanted to be brave, attack them and have our moments. That meant defending one-on-one and we made individual mistakes.
"Honestly, we were not good enough today against a high-quality team. When that is the case, this result can happen."