Paris Saint-Germain have focused their search for a left-back on Atletico Madrid's Filipe Luis, a source with knowledge of the club's transfer plans has told ESPN FC.

Filipe Luis, 33, played the full 90 minutes and was booked in the second half as Atletico returned to La Liga action with a 1-1 draw away at Valencia, and coach Diego Simeone said after the match that Filipe Luis will stay with the club this summer.

However, according to the source, Luis, a versatile left-sided player, has agreed terms with PSG and informed Atletico that he would like to go through with the move before the end of the month.

Atletico, for their part, would prefer not to lose Filipe Luis, who is in his second spell with the club, but they are also aware that they could still make nearly €10 million by selling him.

Antoine Griezmann, Jan Oblak and Juanfran all acknowledged after the draw against Valencia that Filipe Luis has been tempted by an offer from another club.

Filipe Luis, although not PSG's first choice this summer, is now their most realistic target ahead of the transfer deadline on Aug. 31.

Juventus' Alex Sandro was the original priority, but he is now no longer an option, and Borussia Dortmund's Raphael Guerreiro, who coach Thomas Tuchel knows well from his time at the club, is also out of PSG's limited financial grasp.

Atletico Madrid's Filipe Luis has emerged as Paris Saint-Germain's top transfer target. David Aliaga/NurPhoto via Getty Images

Restricted by a lack of clarity from UEFA on their financial fair play (FFP) situation, PSG are playing with less than €20m to fill the void at left-back created by Yuri Berchiche's sale to Athletic Bilbao, said the source, making a veteran such as Filipe Luis the best option -- albeit not the long-term solution Tuchel and sporting director Antero Henrique originally wanted.

Henrique and Tuchel are reassured by Filipe Luis' experience, as well as his familiarity with a number of PSG's players.

Per the source, unless Augsburg's Philipp Max is deemed to provide a better long-term value, the purchase of Filipe Luis will be sanctioned subject to a deal being reached with Atletico between €10m-15m.

At €30m, Bayer Leverkusen's Wendell is too expensive, although a loan with an obligation to buy is still being explored because of Tuchel's liking for the defender. Tottenham Hotspur's Danny Rose remains a potential backup option but has never been a high priority.

AC Milan's Ricardo Rodriguez was discarded as an option after he declared his desire to stay in Italy for at least one more season, the source said, but that could have changed after the arrival of Diego Laxalt, and Inter Milan's Dalbert Henrique, who was once floated by Henrique, has been abandoned.