Former Republic of Ireland captain Roy Keane has slammed their World Cup qualifying defeat to Luxembourg.

Ireland were left with a difficult road to qualify for the 2022 World Cup after an embarrassing loss against FIFA's 98th-ranked nation.

Stephen Kenny's side were clearly void of any real creativity going forward and were punished late thanks to a goal from Gerson Rodrigues.

Manchester United great Keane warned Kenny that there are dark days ahead if he doesn't change his style of play, and expressed concerns over the lack of talent in attacking areas within the squad.

He told ITV: "It was difficult, a tough night last night. Ireland must be rock bottom for the group of players. Real lack of quality. A lot of the players now for Ireland are playing at the Championship level.

"I think the big concern, when your best player, which is Seamus Coleman, is a fullback, it's not a good sign. Tough days ahead. Obviously, he's [Kenny] got his ways, he's trying to play more possession, play through the team. But the stats are scary for Ireland. The lack of goals, the lack of goalscorers.

"I think it's difficult for Stephen Kenny. It's been tough going for him.

"I analyse nearly all the Irish players nearly every weekend, and none of them are doing too much at club level. They're doing OK, and they're honest, but a lot of them are playing in the Championship.

"When they turn up for Ireland, and the manager has them for three or four days, it's very difficult.

"Then when the manager is trying to have this style of play where it's about possession, it's very difficult, especially if the players aren't up to it.

"I got back to it, the best player Ireland have, by far, is Seamus Coleman. He's playing for a brilliant club in Everton but Everton don't play European football, they don't challenge for trophies. It's a long way back for Ireland."