Mark Robins and Lee Bowyer bemoaned refereeing decisions as Coventry and Birmingham battled to a 0-0 draw at the Coventry Building Society Arena.
Ryan Woods was sent off for the visitors for bringing down Ian Maatsen and preventing a dangerous Sky Blues counter attack while Robins claimed the hosts should have had a penalty for a foul by Dion Sanderson on Viktor Gyokeres.
Blues boss Bowyer said: “We’ll appeal that one because that happens in every game, every week.
“I don’t know how many times it happened to Tahith Chong when he was playing for us.
“Of course it was a foul but it’s a yellow card. Ryan knew what he was doing, he was in control of what he was doing.
“Is it nice to see? Not really but it’s part of the game, you take one for the team because he had to foul him.”
Coventry boss Robins felt aggrieved when Sanderson hauled down Gyokeres in the box during a home set-piece but referee Leigh Doughty was unmoved.
Robins said: “We should have had a nailed-on penalty. It was a wrestling match and he (Sanderson) just threw him (Gyokeres) to the ground.
“The sending off was nailed on. I don’t like to see it. It is a cynical, cynical foul and people get injured from that type of challenge from the back.
“You don’t like to see players sent off but that was as cynical as I have seen and that can injure players.
“I was pleased to see him get up from that challenge. We tried to make the extra number count but couldn’t.”
The feisty affair saw Coventry pile on the pressure after the Blues were reduced to 10 men as Gyokeres, Maatsen and Matt Godden all tried to break the deadlock.
Robins added: “We created enough opportunities but didn’t show enough quality in the final third and that was the story of the game.
“They were hanging on at times. We had a load of possession, moved the ball okay, got into good positions but then put the ball into the keeper’s hands from wide areas.”
The draw halted a run of back-to-back defeats for Birmingham after defeats against Reading and Hull.
The depleted Blues are without a host of key players, leading to teenager Marcel Oakley being given just his second career start.
Bowyer said: “You’re playing in a local derby, you’re on the telly, you have to give everything but the important thing is they showed that togetherness and fighting spirit with all the people out.
“Marcel did really well, it was a good challenge for him playing against Ian Maatsen and Jordan James did really well coming on.
“Whenever our keeper [Matija Sarkic] got asked a question he come up trumps for us, I thought here we go when the lad shot over the bar at the end but thankfully for us it went over.
“I thought we done really well, first half we were nervous but second half we were much better.”