The 26-year-old defender has been banned from all sport for that period by UK Anti-Doping (UKAD) after testing positive for benzoylecgonine, a metabolite of cocaine, after Partick’s Premiership game against Celtic on 3 December last year.
Thistle terminated the former Rangers and Dunfermline player’s contract in February.
McMillan claimed he had no knowledge of taking the banned substance and that his drink was spiked accidentally by an acquaintance.
He was quoted in a national newspaper saying that the Firhill club had “hung him out to dry” and that he had been “sacked prematurely”.
A lengthy statement issued by a club spokesman on Thistle’s official website read: “We are extremely disappointed with Jordan’s comments in relation to the way the club handled the situation around his failed drugs test.
“As a club we believe we responded in a fair and thoroughly professional manner to the situation and stand by the action taken at the time.
“It is particularly disappointing to read that Jordan believes he has been ‘hung out to dry’ by the club especially given the fact that we did a great deal to protect both his reputation and career, including but not limited to: As per our duty of care as an employer, the club doctor immediately contacted Jordan to discuss any issues and offer any and all assistance required. The offer of help was not taken up by the player.
“Player confidentiality around this incident was maintained at all times. We were not able to discuss this matter until the decision was published by UKAD.
“The club protected the player in the first instance by citing, at Jordan’s request, personal circumstances as the reason for his omission from match day squads.
“It became obvious that there wouldn’t be a prompt resolution to the matter and, given that club staff were being repeatedly questioned as to the reasons for Jordan’s absence, we simply stated the player was suspended.
“We did not mention any failed drugs test or suspension from football. Jordan and his legal team were kept up to date of all club communications on the matter.”
“Under a player’s contract of employment with any SPFL club, failing a drug test is classed as gross misconduct and clubs have the option to instantly dismiss the player.
“The club refrained from this course of action in the first instance and suspended Jordan on full pay, which continued until his contract was terminated nine weeks later.
“The club offered Jordan a new contract, contingent on a length of ban, which would mean UKAD had taken into account the mitigating circumstances and reduced the mandatory two year suspension.
“This revised contract included a wage being paid to Jordan during the time he was ineligible to play for the club. Jordan rejected this contract.
“Informed Jordan of UKAD’s concerns over the non-specialised legal advice he was receiving, even though we were under no obligation to do so.”
The statement continued: “We regretfully took the decision to terminate Jordan’s contract on 27 February when it became apparent that any decision would be highly unlikely before the expiry of the player’s contract in May 2015.
“We felt we could not justify keeping Jordan suspended on full pay for a total of more than five months, particularly when replacements had already been signed given Jordan’s indefinite absence.
“Partick Thistle Football Club takes its duty of care as an employer seriously.
“In the event of any issues raised by any of our players or staff the club will do everything in its power to provide the help and assistance required, without judgment.”