Radamel Falcao "must be kicking himself" for having passed up a run in the Champions League by joining Manchester United on loan, says Monaco winger Nabil Dirar.
Falcao has scored just four goals for United this season and is expected to be offloaded at the end of the campaign having endured a limited impact in the Premier League.
Monaco, meanwhile, have been the surprise package in this year's Champions League, reaching the quarter-finals where they face Juventus for a place in the last four having disposed of Arsenal in the previous round.
Colombia international Falcao has cut a dejected figure at times this season and made his fifth United substitute appearance of 2015 in the closing minutes of the 4-2 derby win over Manchester City.
Dirar believes Falcao will be ruing the missed chance to play in Europe's premier club competition and contribute to Monaco's run, with United having missed out on qualifying last season, despite his problems during his spell with the principality.
"I think Falcao must be kicking himself [at United]," he told Le Parisien."Here, he would have played and participated in the Champions League, but perhaps he needed more atmosphere. At Monaco, he didn't feel good."
Having edged through their two-legged tie with Arsenal on away goals, Monaco face the much-fancied Juventus in the first leg of their last-eight tie on 14 April but are heavy underdogs against the Serie A champions.
However, Dirar stated confidently: "Juve don't have anything more than Arsenal. For me, the Gunners are even better than them. It's possible. We can go through against Juve.
"I think we mustn't change the system. It's true that sometimes we don't play pretty football but, in Turin, we don't have to score, we only have to defend well. So we can go for the draw."