BBC Sport - French club Lille say they are considering taking legal action after defender Tiago Santos suffered a knee injury from an "uncontrolled and dangerous" tackle against Le Havre on Saturday.
Santos, 24, was carried off on a stretcher having ruptured his anterior cruciate ligament (ACL), as well as suffering a meniscal tear in his right knee.
He was tackled by Le Havre midfielder Amir Richardson in the first half of Lille's eventual 1-0 win and, while it was given as a foul, Richardson did not receive a yellow or red card for the challenge.
Lille said they have asked the league to refer the incident to its disciplinary panel, believing it should have been a red card because the tackle was made "from behind, uncontrolled and in a dangerous manner".
"Beyond the injury itself, the circumstances in which it occurred and the lack of sanction raise serious questions for the club," the club's statement added.
"LOSC has referred the matter to the French Football Federation and the Professional Football League in order to obtain an examination of the handling of this action by the refereeing team and the video assistance.
"LOSC is studying the possible remedies and reserves the right to take any legal action to obtain compensation for its damages."
The club said Santos will be unable to play for "several months".
Le Havre responded by saying that the club and Richardson expressed their support for Santos in his recovery, but backed the decision of the match referee and the video assistant referee.
They also questioned Lille's move to "punish its player after the fact, since such a decision would fall outside the current regulations".
"HAC respects all fellow Ligue 1 clubs and expects the same respect in return," Le Havre added.
BBC Sport has contacted the LFP, which runs the French professional leagues, for comment.
Lille are second in Ligue 1 and face Arsenal in the Champions League on Tuesday.