Meslier has made the number 1 position his own after being asked to replace the Spaniard towards the end of last season.
The 21-year-old has featured in 35 of Leeds’s top flight games and stepped aside on Tuesday evening for Casilla to line up against the Saints.
Bielsa feels that Casilla has been generous towards Meslier, with the season being a difficult one for the Spaniard due to a lack of game time.
“Two pros of a high level. This year’s been a lot more difficult for Kiko, but he was very generous”, Bielsa said at a press conference.
And Bielsa has admitted that he will again hand Casilla an outing between the sticks for Leeds’ final game of the Premier League season on Sunday.
“The fact that Kiko played today and will play on Sunday is a decision that I decided to make concrete.”
Leeds will play an already-relegated West Brom side in their final match of the season at Elland Road with fans in attendance.
