The Brazil international has starred for United since joining from Rennes in 2020.
The 25-year-old Brazilian signed a four-year contract when joining Leeds from Rennes for £17million in October 2020 and talks between his agent Deco and the Yorkshire club about a better deal are ongoing.
Bielsa, whose side return to West Ham in the Premier League on Sunday, said: “I think it’s a great decision. Raphinha is the best player in the team in all the senses.
“Physically he’s the best, technically he’s at the level of the best, his interpretation of the game is very good, very wise.
“He’s in the group of such a powerful nation in Brazil, he shines in the Premier League and he has the attention of all the big clubs in the world.”
Raphinha’s electrifying form for Leeds has been rewarded with four senior appearances for Brazil. He scored twice on his full debut for Tite’s side in a 4-1 World Cup qualifying win against Uruguay last autumn.
Bielsa said: “All of those things are something you guys know as much as me, nothing that I’m saying is new. As a result the decision of the club can only be valued.”
Leeds return to the London Stadium seven days after a 2-0 defeat to West Ham saw them exit the FA Cup at the first hurdle for the fourth season running under Bielsa.
Kalvin Phillips, skipper Liam Cooper, Joe Gelhardt, Jamie Shackleton, Charlie Cresswell and Sam Greenwood remain unavailable, while Diego Llorente and Tyler Roberts are suspended. The latter is also nursing a calf strain.
Leeds are eight points clear of the bottom three, while David Moyes’ high-flying Hammers are bidding to consolidate in the top four.