Lionel Messi will retire at Barcelona, Luis Garcia has said amid doubts over the Argentine superstar's future.

He is the their all-time leading goalscorer and the face of the club but Messi is no certainty to prolong his time at Camp Nou, with his contract due to expire in 2018.

Barca have insisted a new deal remains on course for the five-time Ballon d'Or winner, who joined the LaLiga giants as a 13-year-old.

The uncertainty will only grow the longer Messi's contract situation remains unresolved but Garcia – who emerged from Barcelona's youth system in 1998 before returning in 2003 – cannot see him playing for another club aside from boyhood side Newell's Old Boys.

Speaking to Omnisport, Garcia – who is in Australia working Optus during their Confederations Cup coverage – said: "I don't think he will leave. I think he is happy there.

"Of course sometimes he has to look after himself and his family. I'm sure he is very happy at Barcelona. Barca know how important he is for the club. They will arrive at an agreement. I don't see him playing for another club.

"He has been the face of Barcelona for many years. I think he will retire at Barca. He might finish his international career earlier and maybe go back to his former club [Newell's Old Boys] in a totally different way."

Saturday marks Messi's 30th birthday and he has shown no signs of slowing down – remaining the driving force behind Barca's success.

Since making his Barca debut at the tender age of 17 in October 2004, Messi has gone on to guide the Catalans to 29 trophies, including eight LaLiga titles and four Champions League crowns.

He has netted 507 goals in all competitions – 349 of those in LaLiga – having netted 54 in 2016-17.

Messi is also the only LaLiga player to reach 40 goals in each of his last eight seasons in all competitions, firmly staking his claim as the greatest of all time.

Asked what makes Messi so good in an era that also includes four-time Ballon d'Or winner and Real Madrid star Cristiano Ronaldo, Garcia replied: "He makes football very easy. The most difficult thing is to do things the easy way. It looks so easy when he does it.

"He does everything well. He passes well, he controls well, he scores. When he has to defend, he defends well. So it doesn't matter where you play him. He is going to achieve everything he wants to. When you look at him play, he can do anything. Nothing is difficult for him.

"It's difficult to explain. When you see players in defence or struggling because they are not fast or unable to control, because Messi has an amazing left foot but the right foot is also good. He is small but he is also good in the air and is so clever.

"When he plays in the wide areas, he can go one-vs-one and dribble at players with speed and technique. In the middle, he can assist and keep the ball. He knows when to go fast with the tempo or slow down a little. He can do everything."

Messi has provided Barca supporters and fans from around the world with countless memories and jaw-dropping moments, and Garcia cannot pick one that stands out.

"It is too difficult to pick one. If you have a look at the last goal scored, he was just amazing. Every couple of weeks you see him, he suddenly produces something special," he said.

"You say wow, he cannot beat that and then two weeks after he does something again totally different and you will say again it is impossible to do better, and then he does it. He just produces every week."