The Catalans’ hopes of winning the Spanish title has been dented by Paco Lopez’s men in Valencia and Koeman believes Barcelona’s display particularly in the second half has cast doubt over his future.
Goals from Lionel Messi and Pedri had given Barcelona a comfortable lead at halftime but the visitors allowed Levante to get back into the game as Gonzalo Melero and Jose Luis Morales swiftly scored on 57 and 59 minutes respectively.
France international Ousmane Dembele restored Barcelona’s lead midway through the second half but Koeman’s men once again failed to keep the hosts at bay as Sergio Leon snatched a later equalizer for the Granotes.
"Coaches are always questioned," Koeman said after the game. "But I understand that, after that second half, there are questions.
"We are disappointed and we're wondering what happened. We have to move on and prepare for next season.
"As a coach, you're always responsible. We spoke at half time about improving defensively and not dropping our intensity. We were hopeful, we were 2-0 ahead. You don't expect to draw from there."
"Our aim was to win all three games and hope that the others would lose points," Koeman added. "But now it's difficult.
"Games last for 90 minutes and we lost a lot in the second half. They [Levante] caused problems and we didn't defend well.
"It's very disappointing. It's impossible to understand what happened. It's difficult to explain it."