England manager Gareth Southgate says he knows "pretty much everything" about his players after James Maddison was pictured in a casino despite pulling out of the squad with illness.
Maddison, 22, was photographed on Friday, when England lost a Euro 2020 qualifier in the Czech Republic.
Southgate said the Leicester midfielder will have learned there is "increased interest" in England players.
"That goes with the territory. It's a high-profile position," Southgate said.
"Once a player has been released from the squad, then it's up to them how they spend their individual time.
"I guess what James has learned is that if you have an involvement with England, then there's an increased spotlight on you and increased interest in your personal and private life as well."
Maddison, who has scored three goals and made two assists for Leicester this season, is yet to make his England debut but had been named in the squad for the third time.
On Thursday, he withdrew from the squad for the trip to the Czech Republic and Monday's qualifier in Bulgaria.
"I don't really want to discuss individuals but I know pretty much everything about all of my players," Southgate said.
"I watch every minute of their football, whether that's live or downloaded on a Sunday morning or a Sunday night, or a Monday morning.
"I speak to their club managers, I speak with Aidy [Boothroyd, England Under-21 manager] and all the coaches of the junior teams.
"We never know absolutely everything, but we have a very clear picture of every player, and that's the due diligence that we should always do."