The Latics fell to their third home defeat inside a week against Derby County this afternoon and was jeered by sections of the DW Stadium.
According to The Mirror, chairman Dave Whelan has given into fan pressure by firing the former Burnley and Bolton Wanderers boss, who was appointed in June after Martinez departed for Everton.
Addressing the fans' criticism following today's game, the Scot said: "If it comes through expectation, then so be it. The expectation can only come from being in the Premier League because it's not as if Wigan Athletic have been winning games every week for four or five years, far from it.
"Wigan Athletic have been in the bottom three for the last four, five years and managed a few times to escape and they've done brilliantly to do that. They won the [FA] Cup which was brilliant but they lost their place in the Premier League and with them losing their place, the players, the ones of big value, left.
"It's building that team and putting it together. If people want to be ultra critical, that's the nature of football these days. I'm old enough to deal with that; if they think there's something better that's all well and good. That's why we love football, it's all opinion."
Coyle leaves Wigan 14th in the Championship.