The Brazilian global snubbed a move to United when he left Sao Paulo for PSG in 2013 but it looks like the Red Devils have renewed their interest with widespread reports in recent days suggesting Jose Mourinho has identified him as a January target.
Sources in France believe Lucas is keen to make the move to United, but he won't be forced out by PSG - unless it is a deal that he wants.
The signing of Neymar in the summer has contributed to less game time for the forward who also sees himself behind Kylian Mbappe in the pecking order.
The same article states that the 25-year-old attacker has agreed to the January move given the winger's lack of opportunities at Parc des Princes in the 2017-18 season.
Indeed, per Globo Esporte of Brazil, Moura's former club Sao Paolo are convinced that he will join United for €25m.
According to Jonathan Johnson on ESPN.co.uk, the Brazilian has a number of options if he wishes to escape the French capital, but United are his overwhelming choice if he's to find a new home.
If a move to Old Trafford were to materialise, it could well take place this month.
United have plenty of attacking support in Marcus Rashford and Anthony Martial, but they need an effective No. 10 in the squad.
Additionally, says Sky Sports, the fact that Moura has not appeared in any of PSG's Champions League group matches is another reason for United's interest, as it means that Moura would be eligible for next month's knockout phase.