Lazio boss Simone Inzaghi was left frustrated with their Europa League defeat to Celtic.
The Biancocelesti had taken the lead and were in control only to lose 2-1 in the final stages.
“That's the ugly thing about football, you don't get the results you deserve. It's difficult to swallow a defeat like that," Inzaghi told Sky Sport Italia.
“We must realise that we won't lose many if we maintain this spirit for 90 minutes. It's already happened to us this season, but I couldn't have asked much more from my lads.
“The second goal was an individual error and you pay a heavy price when a player is allowed to lose his marker. It was a performance where we certainly deserved a different result, but we need to keep working, because evidently what we're doing is not enough. We must keep believing in ourselves and I feel we'll go far if we play like this.
“It's a pity, we deserved more in this wonderful arena."