The Italian ace suffered the problem in training on Thursday and he will definitely miss this weekend's clash with Manchester United.
The news is a blow for Amoruso as he had only recently returned from a lengthy lay-off with a knee injury to help Rovers climb away from trouble at the wrong end of the table.
Rovers assistant boss Tony Parkes admitted it was a blow to lose Amoruso and that they were waiting to find out the full extent of the injury.
"It's very disappointing all-round, not least for Lorenzo who has made a superb contribution since returning to the side," Parkes told the club's official website.
"The medical team are looking at the injury, but he won't be available for the Manchester United game on Saturday and could miss the remaining two games beyond that."
