Booth said the result showed his side would compete at Heineken Cup level
London Irish head coach Toby Booth drew encouragement from beating the Ospreys 23-19 on Sunday, even though the result meant his side exited the EDF Cup.
A losing bonus point for the Welsh side ensured it was they who progressed.
But Booth told BBC Radio Berkshire: "It shows we're of the right mettle and it proves we have a Heineken Cup side.
"It also shows me we have a willingness to compete at the highest level. From that point of view, I'm really proud of what the boys have done."
Booth added he was pleased with the players' reaction to their departure from the competition.
"They're very disappointed and I'm glad they are, because it matters to them," he said.
"The mental side of the game is what's really pushing us forward at the moment - our willingness to win everything.
"We're a team that wants to win things. We're turning into a team that doesn't just compete but wins. Momentum is very important."
Bookmark with:
What are these?