Rodney McAree let his Glentoran players know the "harsh reality" if they continue to underperform.
The Glens have now gone three games without a win after dropping out of the Irish Cup following defeat to Crusaders on Saturday.
McAree was left frustrated as another opportunity to bring silverware and European football to The Oval disappeared.
Read next: Tiernan Lynch has a simple message for his Larne players ahead of title run-in
The Oval boss let his players know that they need to turn things around or face the threat of not being there.
"The harsh reality is this is their full-time job and if they don't do it well enough in the long run then they will end up losing their job and someone else comes in to take it," said McAree.
"That's the harsh reality of the business we work in.
"If we don't address it or make it better, ultimately other people lose their jobs as well."
The Glens find themselves 16 points off league leaders Larne going into Tuesday night's game at Carrick Rangers.
McAree has conceded they are unlikely to overhaul the Invermen but still wants his side to finish as high up the table as possible.
"I still think we can finish as high up the table as we want," he said.
"We're not going to win it, in my opinion we're definitely not going to catch Larne unless a miracle happens and we win every game from now until the end of the season.
"We have the capabilities of finishing high up the table, how high will be determined by the players and the effort they put into games.
"We have a tough one coming up but we'll find out a lot about our changing room in that game.
"We will have to look at changing personnel.
"If I was a sub watching that from the bench I would be coming to knock on my door asking why I wasn't playing because the ones in front aren't doing a good enough job.
"Whether they have the mentality to lift themselves when things go against them is questionable.
"We have to question ourselves as staff as well as to whether we can lift them or not.
"They need to be stronger mentally and we need to create more leadership in the dressing room.
"We have niggles and aches and pains but we're not the only club at the start of March who has that.
"You should expect that at this stage of the season so we have to get on with that.
"At this moment in time we're not showing a big enough desire to win games of football."
Elsewhere in the Danske Bank Premiership on Tuesday evening Coleraine welcome Ballymena United to The Showgrounds.
READ NEXT:
Larne boss Tiernan Lynch outlines grounded approach after claiming monthly award
Watch: Donaghadee teen scores wonder free-kick in league game
Ryan Catney on 'dirty player' reputation, Reds exit and being targeted
Michael O'Neill's first Northern Ireland squad recalled as he prepares for return
Sign up to our free sports newsletter to get the latest headlines to your inbox.
