Roger Schmidt blamed a lack of composure in the final third for Bayer Leverkusen's Europa League exit at the hands of Villarreal.
Leverkusen were facing an uphill battle in Thursday's second leg at the BayArena having lost the away contest 2-0 at El Madrigal last week and a goalless draw consigned them to a last-16 aggregate defeat.
The Bundesliga side controlled much of the play, but did little to trouble Sergio Asenjo in the Villarreal goal and the visitors arguably had the more clear-cut chances with Denis Suarez, Roberto Soldado and Manu Trigueros going close.
And Schmidt admits Villarreal were worthy of their place in the quarter-finals over the two legs.
"Villarreal prevailed and they earned it over both games," Schmidt said.
"We have controlled the game, but we were missing determination and clarity in the final 20 metres. We needed some more composure.
"The team gave everything. It was not enough, but we have to accept it."
Defender Jonathan Tah added: "We have given everything and fought until the end.
"Now we must concentrate fully on the Bundesliga. We need to throw everything at that."