Lionel Messi's close-season issues at Barcelona means the 2020-21 campaign could be a difficult one for the superstar forward, says his former Argentina team-mate Emiliano Insua.

It has been a tumultuous period for Messi, starting with Barcelona's humiliating 8-2 defeat to Bayern Munich in the Champions League quarter-finals last month.

Following that humbling experience, Messi shocked the footballing world by requesting to leave Camp Nou and stating he believed a clause in his contract allowed him to leave on a free transfer.

Both Barca and LaLiga disputed his interpretation of the clause, though, saying any team wishing to sign Messi would have to pay his €700million release fee or negotiate a transfer.

Messi ultimately opted to stay this season as he did not want to drag the issue through the courts but he hit out at president Josep Maria Bartomeu in the aftermath of the saga.

The 33-year-old struck a more conciliatory and uniting tone in an interview with SPORT this week and LA Galaxy defender Insua spoke about Messi's enduring qualities, which he hopes he can continue to display after a tough period.

"I think he has everything, he was born like this, the quality he has is amazing, everything he does and has been doing is natural," Insua told Stats Perform News.

"The time I was training with him you can see that. He doesn't train too much, he doesn't need to train too much…[because] this fitness situation he has, he's really quick, really strong.

"Hopefully he can keep showing this because this summer he had a lot of problems in Barcelona, they didn't finish maybe so well in the Champions League.

"Hopefully this year he can be at the same level because I think it will be difficult for him this year."

For a long time it was rumoured Messi may have a new and familiar Camp Nou team-mate in the form of Argentina striker Lautaro Martinez, who was heavily linked with a move from Inter to Barca.

This week it was suggested Barca will no longer pursue a deal after being put off by a €98.5million fee, meaning Martinez is set to continue his promising development at Inter where he has scored 21 Serie A goals in 63 games since joining from Argentine side Racing Club ahead of the 2018-19 campaign.

Martinez has struck up a particularly good understanding with Romelu Lukaku in San Siro and Insua has high hopes he will become one of the best strikers in the world.

"He showed in Argentina that he's a really good striker and he's showing it at Inter," Insua added.

"Maybe everyone expected that he needs time to set up in the Italian league, but he was really fast in the adaptation in the way he was playing.

"The partnership with Lukaku was really good also up front, so they help each other.

"He showed last year he can be one of the best strikers in the world and everyone also said that maybe he's going to Barcelona, now nobody knows anything [on that], hopefully he can keep showing that [form]."