Still buoyant after their comeback at Southampton, Manchester United can land a heavy blow in the Champions League on a team alarmingly vulnerable to comebacks. Paris Saint-Germain visit Old Trafford on the back of letting a lead slip at home to Bordeaux and a two-goal advantage turn into a <a href="https://www.thenationalnews.com/sport/football/neymar-and-psg-stunned-by-monaco-fightback-in-pictures-1.1114931">defeat at Monaco</a>. And that’s just the domestic hinterland, a chill shadow from recent results in a French league that, as PSG’s Neymar put it after Saturday’s 2-2 draw with Bordeaux, “is a competition where we are used to winning a lot of games.” Naturally, PSG having been winning enough to still be top of a Ligue 1 table where they have been champions seven times out of the last eight attempts. But in Europe their margin for error is much slimmer. Defeat on Wednesday, coupled with a victory in Group H for RB Leipzig at bottom club Istanbul Basaksehir, would leave PSG at the uncomfortable mercy of the German and English teams on the final matchday. Even if PSG were to beat Basaksehir next week, they could only leapfrog Leipzig if United, who would have qualified already, win in East Germany. “I’m not worried about the United game,” declared Thomas Tuchel, the PSG head coach, ahead of the expedition to Manchester. He has already given off plenty of signals of deep concern. Against Bordeaux, the two senior components of his defence were rested, with the D-day at Old Trafford in mind. Keylor Navas, the goalkeeper, should return against United, but the match-fitness of defender Marquinhos, who has been struggling with a thigh problem, remains a minor doubt. Tuchel also articulated his specific worries about recent form. His players, he said, have fallen short in attitude, in effort and in discipline. “I usually defend my team, but I can’t do that here. We cannot play against United like we did against Bordeaux or Monaco, and we all have to take responsibility, me included.” Tuchel is well aware that his employers will be ready to hold him to that. One hundred and one days ago, Tuchel, his left foot encased in a protective medical boot, was issuing instructions to the first PSG side to have reached a Champions League final. It was a breakthrough moment for a club who have invested more heavily than any other in individual superstars to establish themselves as part of Europe’s elite. The narrow defeat in the Lisbon final, 1-0 to Bayern Munich, hardly undermined predictions that the club of Neymar and Kylian Mbappe would soar higher now they had taken part in club’s football’s showpiece event. Tuchel’s ankle is well recovered and he can again bring all his wiry energy to the technical area. Fixtures against United tend to raise his pulse. In a very short time, the duel between PSG, a club propelled by new money, and United, a traditional grandee of the European Cup, has developed into a modern classic, a nail-biter overseen by two young coaches, both 47, who came to the profession via very distinct routes. One, Tuchel, has been a manager by vocation since his 20s; the other Ole Gunnar Solskjaer draws on an association with United rooted in a long, heroic playing career. Solskjaer the coach tends to peak against PSG. There was the dramatic turnaround in Paris in 2018/19, when United reversed a 2-0 first leg last-16 stage deficit thanks to an injury-time Marcus Rashford penalty, controversially awarded for Presnel Kimpembe’s handball. There was October’s near-repeat, 2-1 to United at the Parc des Princes, with a late Rashford winner giving Solskjaer impetus in his first group phase as a manager. Since then United have beaten Leipzig 5-0 and taken three points from six against Basaksehir. <strong>____________________________</strong> <strong>____________________________</strong> Since the opening matchday in France, Edinson Cavani, the former PSG striker signed in October, has begun to prove his value for United, too, although the Uruguayan has been the focus of unwelcome attention after a post on his social media account after Sunday's 3-2 comeback win at Southampton <a href="https://www.thenationalnews.com/sport/football/manchester-united-striker-edinson-cavani-apologises-for-social-media-post-1.1120647">included a Spanish term that can be interpreted as offensive</a>. The English Football Association have opened an investigation. A breach of its social media rules can carry a three-match ban. Cavani, <a href="https://www.thenationalnews.com/sport/football/two-goal-edinson-cavani-inspires-manchester-united-comeback-win-at-southampton-1.1119993">who helped set up a goal and scored two after Southampton had taken a 2-0 lead</a>, apologised for what he said had been "intended as an affectionate greeting to a friend". Solskjaer added, "he is really sorry for the mistake he's made, with no malicious intent at all. We support him, but we also support the FA. We want to be in the fight against discrimination. I'm sure Edinson has learned the hard way." Cavani is available to face the club for whom, over seven seasons he scored 200 goals, more than any PSG player in history, and Solskjaer reports he has a full-strength United squad, with David de Gea fit after withdrawing at Southampton with a sore knee.