France coach Didier Deschamps says Barcelona forward Ousmane Dembele must improve his professionalism to make it at the top level.
Sources told ESPN FC last month that bad habits were holding Dembele back at Barca and his punctuality has been the centre of attention this week.
Dembele, 21, didn't turn up for training on Thursday and it took Barca's staff 90 minutes to locate him at home, where the club said he was struggling with a stomach bug.
He then trained alone on Friday and then arrived late for Sunday's loss to Real Betis after being left out of the squad -- although coach Ernesto Valverde insisted he wasn't punishing him.
"Ousmane has been with us for a while," Deschamps said in a news conference on Monday when asked about the player's toils at Camp Nou. "That's his usual trick to be late, although in his defence I'm sure he'll say: 'I'm not the only one.'
"Whether he's at a big club like Barcelona, with the French national team or somewhere else, he has to pay attention to that. It's part of the life and requirements of a professional footballer.
"He must improve to prevent it from becoming negative. These are situations that [have been] repeated. The sooner he understands that, the better for everyone."
Sources have told ESPN FC that Barca are sticking by Dembele, a €145 million signing from Borussia Dortmund in 2017, despite his inability to improve in areas off the pitch which are deemed to be holding him back.
Defender Gerard Pique, meanwhile, says that the players are keen to help him.
"We're all here to help him," Pique said after Sunday's surprise defeat against Real Betis. "We've all been young like him, we've all made mistakes like him."
"From experience, you have to teach [the young players] that football lasts for all 24 hours of the day -- you have to live it from the first minute until the last. I am sure he knows that and that he will keep improving with time."
Dembele was also reportedly late for a team meeting before a Champions League game earlier this season and sources say Barca's concerns over the forward's punctuality and diet date back to when he was sidelined for four months last season.
The France international started the current campaign well, scoring five goals in his first six appearances, but has not started a league game since Sept. 29 since being replaced in the side by Arthur Melo.
He did score in last weekend's comeback win over Rayo Vallecano as a substitute and started against Inter in the Champions League last Tuesday before missing training on Thursday.