As Hearts test looms is O'Neill right to be 'delighted' by Benfica defeat?

Celtic have lost four of their last five matches in all competitions; Martin O'Neill's side return to action against last season's Premiership runners up Hearts in their first Parkhead meeting since their final-day decider; watch Celtic vs Hearts live on Sky Sports from 2.30pm on Sunday

Martin O'Neill wants Celtic to take the positives from a 4-1 defeat to Benfica when they host Hearts on Sunday - live on Sky Sports.

However, is the 74-year-old right to be "really, really delighted" with the Hoops' second-half performance in Lisbon?

The result leaves Celtic with no points from six after two league-phase fixtures in the Europa League and means they have now lost four of their last five matches across all competitions.

Another defeat - fairly or unfairly - also raises more questions over O'Neill's future in the Parkhead hot seat.

It was just weeks ago, following consecutive defeats to Rangers and a loss in their opening Europa League fixture, that O'Neill said he was going to consider his position after a gruelling week. He stayed, and now he must deliver.

Here we answer some key questions as the veteran boss chases another huge result on Sunday...

Following that 4-1 thumping against Benfica , O'Neill hailed Celtic's second-half display and believes they can still progress in the competition despite sitting 34th in a 36-team table.

"The last thing you want to do is concede so early on," he told TNT Sports . "Then at 2-0 we've got a great, great chance to make it 2-1 and within a few minutes they make it 3-0.

"We could have capitulated, but I thought the second-half performance was really terrific. It was a game of two halves. We created chance after chance, we should have scored more goals.

"The second-half performance gives me what I would call the determination, and I think we can still qualify. I know it's down to six games, but we want to qualify for this competition to get into the knockout stages.

"Overall, I'm really, really delighted with the second-half performance, and it's a shame that we conceded the three goals first of all."

In the first half, even when Celtic were not causing their own problems, such as giving away a penalty for the hosts' opener, they were being cut apart at times. That's where the problem lies.

Yes, O'Neill's side could have scored when they hit the frame of the goal in either half - but so could have their opponents.