Wales coach Warren Gatland believes a poor season in Europe for England's club sides could affect Eddie Jones' men during the Six Nations.
Reigning champions Saracens are the only English representatives in the last eight of the European Champions Cup, having scraped through as the bottom seeds, while Newcastle Falcons and Gloucester are through to the Challenge Cup quarter-finals.
Sarries were pushed all the way by Ospreys in Pool 2, the Welsh side holding them to a kick-fest draw in Swansea, only for defeat to Clermont Auvergne in the final round to end their hopes.
The Scarlets won Pool 5 to reach the knockout stages, despite losing their opening group games, and though Gatland is facing an injury crisis in the backs, he is still bullish about Wales' chances.
"I see it from two different angles," Gatland said.
"I look back on the English club form and think that when they have five teams in the quarter-finals of Europe [in 2016], you are looking at a pretty strong England squad.
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"You look now and they have got one team there and they qualified eighth. There starts to be some question marks from my point of view and, I hope, my players. We have not spoken about it but it gives you confidence and a bit of self-belief.
"On the other hand, Ospreys have improved in the last few weeks, good performances against Saracens away and at home, and the score last week [a 24-7 defeat at Clermont] did not reflect their performance, and we have a significant group of players coming into camp for the first time in six years having made the quarter-finals.
"They [Scarlets players] come with confidence and self-belief because of what they have achieved, only the third team in the history of the European Cup to lose the first two games and make the quarter-finals. The performance at Bath was outstanding and they showed character against Toulon, digging deep to grind out a result.
"Players are coming into the squad with a spring in their step and that filters through to everyone."