Liverpool boss Jurgen Klopp has defended Wayne Rooney after he was forced to apologise for photographs purportedly showing him heavily intoxicated while on England duty, stressing players of past years used to "drink like devils and smoke like crazy".

Photos emerged in a report from The Sun which allegedly showed Rooney drunk three days before the international friendly against Spain on Tuesday.

The Manchester United forward is claimed to have attended a wedding held at the national team's hotel 24 hours after Friday's 3-0 win over Scotland.

The 31-year-old issued a statement on Wednesday to apologise for the "inappropriate" pictures, but Klopp was quick to downplay the significance of what happened as he feels worse things took place with previous generations.

"He has apologised for having a glass of whatever? I really feel for the players. There is a human being behind the kid," Klopp said at a news conference on Thursday.

"This generation is the most professional generation of footballers we have ever had. The legends drank like devils and smoked like crazy and were still good players.

"I am pretty sure what Wayne did was not so serious.

"That is the life we live, under a magnifying glass. In one or two weeks no one will remember this."