Manchester - Arsene Wenger is unsure of the welcome he will receive on his final visit to Old Trafford as Arsenal boss on Sunday after many "great battles" against Manchester United during his two decades in charge. 

The 68-year-old Frenchman, leaving the club at the end of the season, will bring a side that is a pale shadow of the team that challenged United's Premier League dominance during his first decade in charge. 

Wenger's clashes with former United boss Alex Ferguson are the stuff of legend and his relationship with current Manchester United manager Jose Mourinho has been laced with bitterness. 

But both men have reached out to him with warm words since he announced he was stepping down. 

Mourinho said he regrets some of the "little negative episodes" between himself and Wenger over the years, calling on United fans to give him a fitting send-off. 

When asked whether he could be friends with Mourinho, Wenger spoke instead of "respect" for the current United boss. 

Arsenal, in sixth spot in the league, look certain to miss out on the top four for the second year in a row. 

But Wenger will still believe he can leave the club with a trophy and a Champions League spot despite conceding a late goal in a 1-1 home draw with Atletico Madrid in the Europa League on Thursday. 

The Frenchman is unsure how he will be greeted at Old Trafford, where he is unlikely to play a first-choice side with the second leg of the Europa League tie looming next week. 

"I don't know what reaction I will get but look we had some great battles in 22 years and for me what will be at stake is to recover from that result (against Atletico) and before we go to Atletico have a good game," Wenger said. 

The Frenchman, who says he is not ready to retire from football, is likely to face a side including former Gunners star Alexis Sanchez, who left to join United in the January transfer window. 

The Chilean's presence in the opposing team will be a painful reminder to Arsenal fans of Wenger's inability in recent years to convince many of his best players to buy into his project and stay. 

Wenger said he was so committed to Arsenal that he even declined an approach by then United chairman Martin Edwards when Ferguson was mulling retiring in 2001. 

"Arsenal is the love of my life. I turned many, many, many clubs down to face the challenge when we built the stadium," said Wenger, referring to the Emirates. 

"I speak to everybody, yes I met Martin Edwards, many people came to see me but I was always loyal to this club." 

"When I look back now I realise what a great team they had," Wenger said of United. "(Ryan) Giggs, (Paul) Scholes, as young players they had (Cristiano) Ronaldo and (Wayne) Rooney and you see what Ronaldo and Rooney went on to do in the rest of their career. 

"(Ruud) van Nistelrooy, all these players together - it was an unbelievable team and I think I realise more with a bit of distance what a challenge it was." 

United are hoping to consolidate their hold on second place in the Premier League, which would mark a significant improvement over last year's sixth-placed finish for the club, who have also qualified for the FA Cup final, where they will face Chelsea.