Bielsa looks unrecognisable ahead of Bilbao return, reveals he watched 380 LaLiga games

The 66-year-old was sacked by Leeds in February after a worrying run of form, leaving the Whites after four years where he cemented legendary status with a long-awaited return to the Premier League.

The Argentine is similarly revered in the Basque country for his two seasons with Athletic between 2011 and 2013, in which he took the side to Europa League and Copa del Rey finals.

Dominating Sir Alex Ferguson's Manchester United 5-3 on aggregate in the Europa League last-16, Bielsa won over fans with irresistibly intense football, and he could now return.

The side from north east Spain are electing a new president on June 24, and should Inaki Arechabaleta win the elections, Bielsa will be coming with him.

Speaking over a video link from Argentina as the candidates put forward their mandates, Spanish outlet Marca said: "This was Marcelo Bielsa in his pure state."

Looking rather trim and clean shaven, Bielsa said: "I am excited to think about joining a group that can give a version similar to the level we had ten years ago.

"I saw the 45 games of the season and I analysed them in all aspects.

"Ten years ago I inherited a great team from [Joaquin] Caparros, but this team is current and is more like what I usually transmit to a team than that of Caparros.

"This team, it has a greater number of players and the quality is comparable. In the last league table, it deserved more than what it obtained. Finishing fifth would have been normal.

"In sprint it is very similar to Leeds, which was my last team, and a very important fact is that 95 per cent of the minutes that the team played were played with 18 players."

Bielsa, well known as a tactical obsessive, described the process of watching every LaLiga game from last season as, 'extensive and laborious', having only become unemployed four months ago.

The Argentine also revealed he already has pre-season planned, despite the fact he hasn't even been named head coach yet.

"A five-week pre-season, the sixth week ends with the first League match," he explained.

"This year will be doubled because there is a World Cup between November and December, and then the training time, with sessions of 60 or 70 minutes, shorter and intense.

"Gym and stretching sessions are recurrent to reduce injuries, as is the daily weight report, based on diet and hydration control."

One of the most interesting aspects of Bielsa's return is his top transfer target, with the former Leeds boss giving a list of targets to Arecheabaleta that included the name of Antoine Griezmann, according to Spanish outlet AS.

Athletic employ a policy where they only sign players born in the Basque region, which would seemingly rule the Frenchman out, however it turns out that isn't the case.

The Atletico Madrid striker, on loan from Barcelona, was born in Macon in Burgundy, hundreds of miles from the French Basque country, but so was Bixente Lizarazu who also turned out for the Lions.

Athletic's rules state that they can sign players who have been raised in the region, as is the case with Griezmann, who joined rivals Real Sociedad aged 13.

The finances would make the signing incredibly unlikely, but it just shows how keen Bielsa is that he's lining up players many didn't even know were eligible.