The club's fans are more than happy to overlook the fact he has never scored in nearly 300 appearances because few players are as important to the Spanish champion.
Having already proved his flexibility over the years, the 32-year-old Mascherano is now learning another position.
Mascherano is defying his age and increasing his worth in a team whose intricate passing style is incredibly demanding on players.
The Argentina international has become coach Luis Enrique's fix-it man. Already able to play either in midfield or as a central defender, Mascherano has now passed the test as Barcelona's right back.
He has filled in expertly for the injured Sergi Roberto, both as the right-sided defender in a backline of three, or in the four-man defense Luis Enrique used to thwart Manchester City on Wednesday in the Champions League.
Enrique said on Friday that Mascherano may play on the flank for Saturday's visit to Valencia in the Spanish league.
"The option of Mascherano is open," said Enrique, who rarely reveals his lineups before the match. "He played a good match against City and he is one of the possibilities that I have for this and other matches."
Wherever he plays at Valencia's Mestalla Stadium, Mascherano will be tasked to hold down a back line that will be without the injured Gerard Pique and Jordi Alba.
Against City, he nullified winger Manuel "Nolito" Agudo and also set up Barcelona's opening goal. Stealing possession in City's half he sprang a quick attack that resulted in Lionel Messi's first of three goals in a humbling 4-0 loss for former Barcelona coach Pep Guardiola.
Mascherano's value is his versatility and willingness to sacrifice for a team full of incredibly talented individuals such as like Messi, Neymar, Luis Suarez and Andres Iniesta.
It was Guardiola who gave Mascherano the first opportunity to reinvent himself at Barcelona when he was struggling to find a starting role.
Having arrived from Liverpool in 2010, he found Sergio Having arrived from Liverpool in 2010, he found Sergio Busquets well entrenched in his own position of holding midfielder.
It was a simple choice: adapt or fail. So when a spate of injuries left Barcelona without a central defender, he seized his chance.
Mascherano compensates for a height disadvantage with intelligent play, such as when he anchored the side that beat Manchester United 3-1 in the 2011 Champions League final.
"I never thought I would be here this long," he said. "I know what I can do, but I also know the demands that Barca places on you. In any other team I would have liked to play in midfield, but changing positions was worth it to keep playing here."
Mascherano plays in midfield for Argentina and is a key player for the side that reached the final of the 2014 World Cup, losing to Germany.
His latest positional change for Barcelona goes against a customary trend. The usual evolution of aging defenders is changing from a wide position to slot inside, compensating for dwindling speed.
Barca's coach saw the potential for Mascherano to do this when Roberto injured a leg muscle earlier this month.
He looked past Roberto's natural replacement, Aleix Vidal, and asked Mascherano to take on the role. Luis Enrique liked the result, so even with Roberto cleared to play against City, he left Mascherano in his place.
Mascherano's industry more than makes up for the fact he has not scored in 290 appearances â a Barcelona club record for an outfield player.
"I am not obsessed with it," he said. "A goal wouldn't change my life." Mascherano's contributions, which have helped win 17 titles, are fully appreciated and he signed a new contract on Monday until 2019. "My time here at Barcelona has been magical," he said. "Year after year the team has kept its hunger."