The Clydesdale Bank Premier League champions were trailing to Simon Lappin's first-half strike during Saturday's 1-0 defeat by Motherwell at Parkhead when the club's top scorer was replaced by Georgios Samaras on the hour.

Amid a chorus of boos aimed at the Parkhead boss, McDonald, who has scored 26 times this season, showed his own feelings as he threw his tracksuit top away in anger before kicking out at a dug-out seat.

However, the former Motherwell striker, one of the nominees for the Royal Mail PFA Scotland Player of the Year award, apologised for his behaviour and stressed that he has no hard feelings towards his manager.

"It was nothing to do with the team or the gaffer, it was just my passion for playing for the club," said McDonald.

"I wanted to stay out and try and turn the game around for the team and myself.

"He (Strachan) made the decision for the team and I've got to understand that.

"I'm part of that team and when you do what I did it creates a negative reaction all round the stadium.

"That was incorrect for me. We are all in it together and you have to get behind the 11 players who are on the park at that time.

"No player is happy coming off when the game is in the balance but in saying that, my reaction was totally incorrect.

"I apologised to my team-mates and manager straight after the incident and then again when we went in to the changing room.

"No player should do that and I'm fully aware of that. I'm 150% behind my manager and everyone at the club.

"The gaffer signed me and has a lot of faith in me and believes in my ability.

"So to clarify, I put my hand up and apologised for what some people would call my petulance."

McDonald added: "Credit to the gaffer and the way he dealt with it. We continue to work together and we go forward from there.

"It's not the first time you've seen this from a player and I'm sure it won't be the last."

Strachan's future at Celtic Park is under scrutiny as he faces the prospect of losing the SPL title to Rangers who are seven points ahead with a game in hand.

As the seconds slipped away near the end with no prospect of an equaliser on the horizon, a crude chant advising Strachan to leave the club was drowned out by other Hoops fans giving support to their team.

McDonald played down the speculation surrounding Strachan by saying: "As far as we are concerned he is our manager and he will be next year and beyond.

"I know it's not up to us but we are more than happy with what he is giving us and he is happy with what we are giving him.

"We are going through hard times at the moment but his record speaks for itself, doesn't it.

"At times it's difficult to put your finger on why it's not happening but the team spirit is great.

"There have been times when we just haven't got over that line this year and that's why were are in the position we are in at the moment.

"But there are still a lot of games to be played between now and the end of the season."

McDonald remained realistic about Celtic's chances of retaining the title.

He said: "We are realistic, we know it's going to be difficult to catch Rangers now.

"It's up to them to keep performing and all we can do is win our next seven games.

"It's not over until it's over but we certainly can't afford to slip between now and the end of the season.

"We need to win all seven games in order to have any sort of chance. I don't see why we can't do that."