The Argentine ended his first season in Dubai without a trophy after they suffered a stunning defeat on penalties in the Gulf Clubs Championship decider
Maradona's side had enjoyed a 3-1 advantage from the first leg in Bahrain, however the visitors turned the tie around with an early Jamal Braro goal.
However the pivotal moment came in the seconds following the strike, when Al Wasl keeper Majed Nasser headbutted Ismail Abdullatif as he tried to retrieve the ball from the goal, earning him a straight red card.
Rashid Essa also was sent off for a headbutt on 78 minutes with the scoreline at 3-1, in response to Rashid Abdulrehman's foul, leaving Maradona to rue indiscipline.
“The red card and the first goal were very important factors,” Maradona told reporters at the post-game press conference.
“We had to pull one player out from the midfield and change our tactics. We had a certain plan but this made it very difficult for us to continue and we had to change.”
Al Wasl midfielder Mariano Donda was clearly fuming when he spoke to reporters.
"Soccer is for intelligent players. That is why we lost. Don't say hard luck," Donda said.
Maradona added: "Muharraq deserved the win. They took the match out of our hands, they took control of the midfield.
"If they were a bit more focused and organised in their tactics, they could have won it before the penalties.”