Speaking to BBC Sportsound, O’Neill was asked whether having players with more European experience, or those capable of performing at a higher level, might have produced a different outcome.

O’Neill replied: “I wouldn’t go down that path at this minute. We have what we have. We have to try and compete.”

The Celtic manager admitted some of his players were short of experience at this level.

O’Neill said: “It’s a good point you make, you know, it is tough for us. It is, there are some fine sides playing in European football, and, but tonight, I thought we competed strongly.”

He added: “We’ve got some players here who have maybe not as much European experience as you would want.

“These games are tough, home or away.”

O’Neill felt Celtic could have won the match had Liam Scales scored with his header that struck the crossbar in the 63rd minute.

He said: “I felt myself, that had we got the second goal in the game, Scales’ header hits the bar, that we probably would have gone on to win.”

Celtic couldn’t recover from Rodriguez’s double, which wiped out their lead in the space of three minutes.

After the 4-1 defeat to Benfica, O’Neill revealed what he told his Celtic players in the dressing room and said he had remained positive despite the scoreline.

Celta Vigo statistics highlight Celtic’s European struggles

O’Neill called it a “really tight game”, although Celtic were outshot by a wide margin. The BBC recorded 22 attempts for Celta and eight for Celtic. The visitors also had 56% of the possession.

The xG figures were 1.21 for Celta and 0.51 for Celtic. Scales’ header was a big opportunity to make it 2-0, but Celtic struggled to create openings of their own.

Dane Murray, Colby Donovan and Callum Osmand were all in O’Neill’s starting eleven, and none have extensive European experience.

That’s nine goals conceded across the games with Ferencvaros, Benfica and Celta Vigo.

O’Neill wouldn’t be drawn on whether the squad is good enough. He admitted some players lack European experience, but Celtic’s numbers against Celta Vigo suggest there are problems beyond that.