Defender Liam Scales insists Celtic can still progress to the Europa League knockouts despite a hugely disappointing start to the competition.

Thursday's 2-1 defeat by Celta Vigo was Celtic's third defeat in three Europa League matches, leaving Martin O'Neill's side 35th in the 36-team table.

Following losses against Ferencvaros and Benfica, Celtic took the lead against Celta through Mika Baur before conceding twice in three minutes.

The Scottish champions were booed at full-time - not for the first time this season - but Scales says there is no sense in negativity.

"We still have five games left so we have to stay positive and there's still obviously enough points up for grabs for us to qualify," he said.

"So as long as that's the case, I think we have to try and stay positive.

"It's not that hard [to stay positive], we've played against good teams.

"I think we're still sort of a work in progress, we're not the finished package yet.

"It's been a tough start. But we have to we have to keep bouncing back and keep our domestic form right and, hopefully, I think we just need a bit of momentum now in this [Europa League] tournament.

"I think you probably have to be just be a bit sharper on and off the ball.

"You get punished for your mistakes at this level and I think minimising mistakes and just making good decisions all over the pitch really, that's what we need to do better."