Struggling Jets, currently seventh in the 13-team Northern Conference of the Nigeria National League (NNL) - Nigeria's second tier - have also snapped up a further 10 new players to increase competitions and "separate wheat from chaff."
"We had a big squad of 65 players, too crowded and unproductive, so we had to release 40 players," the club's sporting director Benedict Akwuegbu told BBC Sport.
"We only need 35 players for the season and some players were not even registered but training with the club. It was just too much.
"What we've done is retain the ones who have something to offer and bring in ten new players as well. It's like separating wheat from the chaff.
"The atmosphere has changed now and we now have a squad capable of fighting in our tough quest for promotion."
One of the players affected told BBC Sport that he was not given enough opportunity to prove himself.
"I understand that the team was struggling but I didn't really get a chance," said the defender, who requested anonymity.
Another player, also speaking on condition he is not named, said, "I believe the club made their own decisions, but I will hopefully come back and play against Jets someday and prove they were wrong to let me go."
Former Nigeria international striker Akwuegbu insists the club will still release some players at the end of the season.
"Right now our chances of promotion is very slim this season but we are still going to release some players," he said.
"There's no sentiment and you only need the best players to achieve your goals and not a big squad."
Mighty Jets will host highflying Adamawa United FC of Yola later on Thursday in an NNL fixture.
Mighty Jets won the Nigerian Professional Football League (NPFL) league title in 1972.