Lionel Messi pushing hard to recover from calf injury to be fit for Barcelona's La Liga opener at Athletic Bilbao

Argentine striker misses emphatic pre-season win over Napoli as he looks to recover from calf tear

Antoine Griezmann celebrates his first Barcelona goal. AFP

Barcelona fans in Michigan. AFP

Suarez finds the net. Reuters

Suarez runs away in celebration after finding the net. AP Photo

Barcelona's players pose with their trophy after winning the La Liga-Serie A Cup match. AFP

Barcelona's players were in high spirits after beating Napoli. AFP

Barcelona's bench in a relaxed mood. APF

Napoli manager Carlo Ancelotti. AFP

Barcelona's players pose before the game. AFP

Barcelona players celebrate. AFP

Griezmann reacts during Barcelona's win over Napoli. AFP

Griezmann celebrates with Luis Suarez. AFP

Suarez is surrounded by Napoli defenders. AFP

Ernesto Valverde, second left, watches his Barcelona side in action. AFP

Suarez looks to find a way through on goal. AFP

Gerard Pique shows his frustration. AP Photo

Ousmane Dembele, left, celebrates his goal with Griezmann. Reuters

Suarez looks to find space. AFP

Lionel Messi is training hard in his bid to be fit for the start of Barcelona's La Liga title defence on Friday against Athletic Bilbao.

The Argentina striker has not played any part in the club's pre-season programme, having suffered a Grade 1 calf muscle tear in his first training session back at the club on Monday.

Barcelona released video of Messi training on his own as he looks to get his fitness up to a level where he can be part of the squad against Bilbao.

Messi, 32, had said at the time of the incident on social media: "I wanted to get started and unfortunately I had a mishap during the first training session which will keep me out of action for a while."

Messi had been late back to pre-season after being part of Argentina's run to the Copa America semi-finals in June and July.

He had made his first appearance at the club's home friendly against Arsenal last Sunday, speaking to fans on the pitch as he spoke of his "renewed dreams" for the club after their disappointment at losing in the semi-finals of the Uefa Champions League in May.

"It's hard to say something after last season, but I don't regret anything," the 32 year old said.

“But I have no doubt that together we are going to fight again for everything. We won eight League titles in 11 years. We do not give it the value it deserves but over the years we will see how difficult it was.

“This club fights for everything and this year will be no different. We have renewed dreams."

Messi missed Barcelona's pre-season tour to the United States and Ernesto Valverde's men completed a successful week with a 4-0 thrashing of Napoli in Michigan on Saturday.

They had beaten the same opponents 2-1 on Wednesday in Miami, but proceedings were more emphatic this time around.

Luis Suarez scored twice, while Antoine Griezmann scored his first goal in a Barcelona shirt since his move from Atletico Madrid.

Ousmane Dembele completed the scoring for the Catalan side, who now return home to prepare for the clash with Bilbao.

Check out a gallery of the action from Barcelona's win over Napoli above. To move on to the next photo, click on the arrows, or if using a mobile device, simply swipe.