The Whites missed the chance to move top of the Championship this morning by losing 2-1 away to Blackburn Rovers.
Darragh Lenihan struck the winner on 70 minutes, after Mateusz Klich had cancelled out Rovers' second-minute opener through Danny Graham.
Clarke, a 17-year-old academy graduate, has previously impressed in a cameo role against Brentford prior to the international break, and Bielsa gave him another 15-minute stint today.
And it looks like the veteran Argentine was impressed with Clarke, who replaced Stuart Dallas.
"What Pablo did on the pitch was important. Jack Clarke also had a positive influence on the game," he told a press conference, via Leeds Live.
"What we can say is we can blame a loss against a rival that is not better than us. That’s not a good point."
Clarke is certainly one to watch in the future, but it's indicative of Leeds' dwindling attacking options that Bielsa is forced to rely on a teenager to be a game-changer.
Bielsa had Kemar Roofe back after missing over a month, but Patrick Bamford remains injured, while Pablo Hernandez only managed a 20-minute cameo after he too spent a while on the sidelines.