The 'captains' pick' match was expected to be played on March 7 or 8, one week before the commencement of the 2014 home-and-away season.
McLachlan stressed how important it was to have the competition's best players available for the concept to succeed and said it was 'increasingly unlikely' to happen despite having the support of the AFL and the players' association.
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"Things evolve and we are not going to do it unless the whole industry has bought in and we have our best players playing," McLachlan said.
"If you look at the media commentary out there at the moment, the players are on board but again we have this problem with the clubs not buying into it.
"We won't do anything unless we have everyone on board and this is looking increasingly unlikely."
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Representative football has been in the spotlight over the past week after the Indigenous All-Stars lost the International Rules series 2-0 and by a combined total of 101 points to Ireland.
McLachlan was 'disappointed' by the side's performance but threw his support behind the hybrid concept, reiterating that it would succeed if the best players were chosen.
"It would be incredibly disappointing if that was the end of the IRS," he said.
"I think we have strong support at AFL house and through the playing group and I've had a number of ex players say it was one of the best things they did in their football careers.
"We would love it to continue, the Irish want it to continue but we have to work the players, with the clubs and with the Irish to get a series where the best players are playing.
"If it does, it will be a success like it was for many years."
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