Martin O’Neill has hit back at the mounting suggestions that Celtic are now a Jekyll and Hyde team under his management.Thursday’s home defeat to Celta Vigo in the Europa League left the Parkhead men without a win in their three group matches, with a dismal run on the continental stage extending to the collapse away to LASK in the Champions League play-off.O’Neill’s men are now sitting in 35th place in the 36-team group – with FC Ararat-Armenia the only team beneath them.Celtic, though, remain top of the Premiership heading into the weekend, with a home loss to Rangers the only reverse they’ve suffered in nine matches.Such contrasting form has led to many observers questioning why a side which remains the team to beat domestically is repeatedly failing to turn up in Europe.O’Neill, though, feels the disparity is less to do with his side’s mentality and more to do with the step up in the standard of opposition. Martin O’Neill was frustrated after Celtic suffered a third consecutive Europa League defeat Celta Vigo defender Javi Rodriguez celebrates after claiming his second goal of the eveningAsked if he subscribed to the view that he was in charge of a Jekyll and Hyde team, he insisted: ‘I don’t think it is. Benfica won again on Thursday night. I see LASK won in the Champions League.‘We are up against reasonable opposition. I thought the other night was the night to get off the mark.‘Is Europe a step too far for us? I’m hoping not. It might be right at the end of it all but I don’t think so.‘You want to compete. I’m not saying it should be an absolute joy, but it should be a spur to play in these games against really decent opposition.‘There’s no question the European games are a step up. They (Celta) are playing in the Spanish top division and have some decent players.‘They have some younger lads and then the experience of (Iago) Aspas and sometimes you need a bit of experience around you.‘They are decent, but I believed they were beatable the other night, and that’s the disappointment. But you do learn, even I am still learning.’Celtic next face Besiktas at home with trips to face Portuguese outfit Torreense and Omonia arriving before Christmas. The group campaign concludes with a home match against Marseille and an away game with Union SG in January.Although aware that his side will probably need to pick up ten points from those five matches to stand a chance of progressing, O’Neill is not without hope.‘I know it’s easy for me to say, but Celtic will be back,’ he stressed.‘You can definitely learn a lot from the European games. Like last season against Midtjylland, we were physically blown away. But we fought back and got some good results. That’s what we want to try to do again.‘It’s easy for me to say, but if we can get up and running there’s still a chance. It didn’t happen the other night, but we’re still not out of it in terms of the points we can gain.‘But each game that passes when we don’t get on the scoreboard, it becomes more difficult.’ O’Neill insists his Celtic side can still qualify but concedes they need positive results soonCeltic now need to dust themselves down and go again at Easter Road on Sunday, O’Neill’s men bounced back in style from the loss to Benfica with a 7-1 demolition of Hearts and the manager is looking for a similar response.‘You can’t have excuses going into Sunday,’ O’Neill stressed. ‘That’s how the club is built. You need to be competing.‘We have to physically recover and get ourselves right for the game at Hibs. I don’t think the other night will cause us any serious psychological damage.‘You never know, it’s a tough old schedule for us. It’s been a tough week with going to Portugal and so on. But no excuses. We are where we are and we have to try to win. Sunday becomes a big game for us.’Not included in the European squad, Jota will be available for Easter Road.Cameron Carter-Vickers and Alistair Johnston are in contention to return after injuries although Auston Trusty will be absent for a spell following the death of his father.‘I think having those two lads and Jota will definitely be a real plus for us in the coming weeks,’ said O’Neill.‘Cameron and Alistair are coming back from hamstring injuries so we will have a look and see if they are available. Hopefully we’ll have Yang (Hyun-jun) back in a few weeks as well.‘Obviously, you are aware of Trusty’s situation. He’s very, very down, which is totally understandable.‘We’ll have to see what he wants to do. I don’t want to talk out of turn but I think there will be a celebration of his father’s life that he’ll want to go out to. We’ll give him time and see how he is.’