Melbourne Heart coach John van 't Schip has called for more discipline from his players following a couple of key suspensions in recent weeks.

Central defender Michael Beauchamp received two matches on the sidelines for an off the ball incident involving Central Coast Mariners midfielder Oliver Bozanic on September 10 before experienced left-back Dean Heffernan copped a red card after two bookable offences in the 4-0 loss to Brisbane Roar on the weekend.

van 't Schip says it does not reflect well on the club and has urged his players to be smarter when making challenges.

"It's negative for the club, it's negative for the team and it's negative for themselves," the Heart coach said.

"A red card, that's part of the game, but there are different kinds of cards you can get.

"Getting a red card for talking, knowing already you have a yellow card, that's not real smart," he said, referring to Heffernan. "You can't change that.

"The only thing is we must be aware of it for the rest of the season because we need all the players as much as possible, especially in the back.

"Michael Beauchamp, he knows it," he added. "The first thing he said was it wasn't good and not that smart and, 'It was stupid of me and I apologise'.

"So they know it, but it's something that's game preparation.

"Before a game you prepare yourself so that you can have decisions you don't like or have a player saying something that irritates you, but if you react that's what they want.

"That's part of your professional behaviour."