Barcelona's move for Antoine Griezmann does not rule out the possibility of signing Neymar this summer, although the Spanish champions will wait for Paris Saint-Germain to come to them, various sources have told ESPN FC.

Both Ernesto Valverde and the club's sporting structure -- including sporting director Pep Segura, technical secretary Eric Abidal and his assistant Ramon Planes, who are working hard on bringing in new players -- have given the green light to adding both forwards to the squad during the transfer window.

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While a deal to bring in Griezmann from Atletico Madrid is progressively advancing, with the transfer set to be announced within the next week, the situation with PSG attacker Neymar is moving much slower.

ESPN FC learned last month that PSG are open to selling Neymar and sources with knowledge of the situation at Barca have said the Catalan club are waiting for the Ligue 1 side "to open the door and invite negotiations" for the Brazil international.

The same high-ranking sources inside the club added that "it's a complicated situation, but [signing Neymar] is not impossible." They add that they have looked over the figures and can afford the operation, providing there are more sales this summer.

Vice president Jordi Cardoner said last week that Neymar wants to come back but Barca are demanding he fulfils a range of conditions to help facilitate a Camp Nou return and reduce the tension with the supporters. There is still some disappointment about the way he quit the club for PSG in a world record €222 million transfer in 2017.

The Blaugrana want him to show that he regrets the way he left. They are also looking for him to commit to living a more professional lifestyle away from the pitch as there are doubts about how he chooses to spend his private time.

The sources add that Barcelona still feel Neymar "is a different type of player" who can offer something unique. They believe having Neymar and Griezmann join up with Lionel Messi and Luis Suarez would be a "blessing" for Valverde, who would be tasked with fitting "one of the most feared attacks in history" into the same side.

ESPN FC reported two weeks ago that one of the keys to any potential deal for PSG would be the inclusion of Barcelona players on top of any transfer fee. Philippe Coutinho, Samuel Umtiti, Ivan Rakitic and Ousmane Dembele could all be used as makeweights, it has been suggested, although it is not something the players have been approached over yet as Barca await PSG's move.

Meanwhile, Barca should finalise the €120m signing of Griezmann next week after his buyout clause dropped from €200m on Monday. They will not pay a penny more than the France forward's clause, but would be open to negotiating with Atletico if it meant they could pay in instalments.