The former Cardiff City boss has apologised for sending messages that were "disrespectful of other cultures", with an LMA investigation concluding that the incidents were no more than "friendly text message banter".
However, retired footballer and LMA member Rosenior has blasted the organisation for referring to apparent racism as "banter".
"In over 70,000 text messages I've sent I've never used inappropriate language and I'm sure neither has the vast majority of people," BBC Sport quotes him as saying.
"If Malky did use a couple of texts, as he admits to in the statement, then I'm disappointed and I think it needs to be dealt with not as something swept over or as a bit of banter.
"I know [the LMA] are trying to protect their member but in doing so I feel they are almost abusing another member, like myself."
Allegations that Mackay exchanged inappropriate texts with former colleague Iain Moody came to light when Cardiff submitted a dossier detailing the alleged misconduct to the Football Association, a move that is thought to have cost him the Crystal Palace job.