The substitute was shown a straight red card around an hour into what became a 3-0 defeat at Elland Road.
Struijk won the ball cleanly and Pawson allowed play to continue but when, alerted by the response of Mohamed Salah and the Liverpool bench, he saw the extent of Harvey Elliott’s injury, Struijk was dismissed for “the intensity (of the tackle) and endangerment of Elliott”.
Elliott dislocated his ankle in an incident Sky TV refused to show replays of because of its gruesome nature. Video assistant referee Peter Kirkup did see them, and backed up the Sheffield official’s decision.
But opinion was split, with television pundits Gary Neville and Jamie Redknapp – who also had the benefit of replays – concluding Struijk was blameless.
Bielsa saw it slightly differently.
“Pascal recovered the ball,” he reflected. “But I have the feeling the movement of the rest of the body after he recovered the ball made him hit Elliott. I’m totally sure there was no bad intention.
“I regret that such a young career at such a high level has been interrupted and I hope he’s able to come back.”
Asked if there was any possibility Leeds would appeal the decision, Bielsa appeared to discount it.
“For me the referee decides,” he insisted. “He has enough resources to make a decision. I never like to question the decision the referee makes.”
With Struijk set to miss the next three matches through suspension, the first-half injury to Diego Llorente became even more damaging. The Spanish centre-back picked up a muscle problem, the same reason Adam Forshaw missed the game.
Goals from Salah – his 100th in the Premier League, Fabinho and Saido Mane’s stoppage-time effort left Leeds winless after four league matches this season.