After watching his side go down 3-0 to Sweden, Wales manager Chris Coleman admits they may have been suffering from some complacency ahead of the match.
Sunday night's defeat means the Dragons have failed to record a win in four consecutive matches, suffering three losses and one draw, since qualifying for the European Championship.
Coleman feels is exactly what his side needed to sharpen them up for their tournament on 11 June against Slovakia.
"We get a bit of success, a bit of expectation, sometimes a little bit of complacency and that can give you a little slap in the face," he told the BBC.
"Maybe that's what's happened to us, certainly today."
In defense of their performance, Joe Allen, Joe Ledley and Hal Robson-Kanu made no appearance in the match, while Gareth Bale only came on in the second half.
"We were a little bit naive, which would be my criticism today," Coleman continued. "Normally we do a lot to work on being a bit more streetwise on the pitch, like Sweden were.
"We saw how many times they fouled us on the counter-attack to break it up. There's nothing wrong with that – that's international football.
"I'd rather that today than me sitting here next week complaining about the same problem.
"The boys are disappointed because they know they can play a bit better than they did in certain areas," he added.
"In saying that, we've got a huge week in front of us – and I'm very positive."