Rosenior and Sam collided on the edge of the United penalty box in the closing stages of a lively encounter on Tuesday night, leaving the Tigers right-back needing lengthy treatment before departing the KC Stadium on a stretcher in stoppage time of the 2-2 draw.
Sam used his Twitter account on Wednesday morning to say: "It was unfortunate what happened to Rosenior last night, I never saw him coming then we collided and his injury looked bad..complete accident."
But Pearson was unequivocal in his take on the matter when speaking after the game. Asked about the defender's condition, he said: "We don't know yet but I'm not happy about the challenge.
"I've just seen it, I didn't realise how bad it was at the time but he's led with his arm. It's a bit of a coward's challenge, unfortunately."
Asked where Rosenior had been injured, Pearson added: "Neck, so we'll have to see how he is. He's conscious now - shocking challenge."