Barcelona have not begun contract renewal negotiations with Lionel Messi and Paris St-Germain are "looking closely" at the situation, says Spanish football expert Guillem Balague.

The Argentine forward, 33, is out of contract this summer and has yet to agree an extension.

A number of players could leave the La Liga club in the coming months.

"Messi will monitor the next two weeks when big club decisions will be made," Balague said.

Messi sent a fax to Barca in August 2020 saying he wanted to exercise a clause in his contract which he said allowed him to leave for free.

But the club said his 700m euro (£624m) release clause would have to be met.

He ultimately stayed with the La Liga giants, saying it would be "impossible" for any team to pay the fee.

Messi said at the time that the fact he did not tell Barca he wanted to leave before 10 June was crucial, and had he done so his release clause would not have had to be met.

Manager Ronald Koeman said he hoped Messi had not played his last game for Barca at the Nou Camp following their 2-1 home defeat by Celta Vigo on Sunday, but the striker has been granted an early holiday and will miss the final game of the season against Eibar.

The loss ended their title hopes and means they will finish outside the top two for the first time since 2007-08.

"He will have to decide if he wants to be in the club for a couple more seasons as a rebuild is taking place or if he wants to help PSG to win Champions League titles," Balague wrote on Twitter.

"Nobody can guess what he will decide at this point."

Barcelona generated more money than any other club in Europe during the 2019-20 season, but still had the second-largest revenue fall in absolute terms.

The club have amassed a huge amount of debt because of the coronavirus pandemic and heavy spending on player transfers.

Balague believes that "15 to 17" players could leave the club this season, including Spanish centre-back Gerard Pique and compatriot Jordi Alba.

"Centre-backs is one of the priorities. The club wants to save Pique's wages and will bring Eric Garcia," Balague said.

"[They are] also interested in Lisandro Martinez [Ajax], who can play full-back and centre-mid."

Striker Sergio Aguero, who will leave Premier League champions Manchester City at the end of the season, is one of Barcelona's targets.

Barca will also discuss potential swap deals with Inter Milan and Juventus, with Juve's Dutch centre-back Matthijs de Ligt high on the list.