Celtic need skipper Scott Brown for his football as much as his passion in the William Hill Scottish Cup semi-final against Rangers on Sunday, according to former Hoops assistant Johan Mjallby.
The Ladbrokes Premiership champions are planning to appeal against the late red card the midfielder received for a tackle on Liam Boyce in the 2-2 draw at Ross County on Sunday.
The offence would normally trigger a two-game ban, but the Scottish Football Association informed clubs in advance that all disciplinary hearings for incidents this Easter weekend would take place on April 28.
Celtic remain unbeaten domestically this season and are within two games of clinching the treble.
Speaking at a William Hill media event at Hampden Park, former Celtic defender Mjallby, currently manager of Swedish side Vasteras SK, spoke of the importance of Brown in that quest.
He said: "He has drive and passion and his leadership qualities are second to none.
"He is very important member of this team, not only being the captain, as a footballer he sometimes doesn't get the credit he deserves.
"He is an aggressive player and he used to probably be more hot-headed than he has been in the last couple of seasons.
"He over-reacted and that was the wrong thing to do, but I don't mind, I like it, it is something you need to have inside you."
Mjallby was as baffled as anyone at referee Don Robertson's decision to award a spot-kick for to the home side after County's Alex Schalk went to ground inside the box without being touched.
Boyce converted the spot-kick to earn the struggling Staggies a valuable point.
The former Sweden defender, however, refused to give credence to age-old anti-Celtic conspiracy theories.
He said: "Not at all. I don't think so.
"You can see that it wasn't a penalty, but it happens
"It is a very pressurised job to be a referee, but you try to do the best you can.
"This time he went against Celtic, but if you look through at all the games - down in England at the weekend you can probably see a few penalties that shouldn't have been given either.
"It is part and parcel of the game and I don't think you should spend too much energy on it.
"It has never been a problem for me as a player or when I was assistant manager at Celtic.
"Now and then you will obviously be upset by decisions, but we are all human. It is something we need to accept. "
Mjallby was in the last Celtic team to win the treble, under Martin O'Neill in 2001.
He expects Brendan Rodgers' side to equal that achievement this season.
"I do," said Mjallby. "After the form they have shown this season and the players they have at their disposal and obviously a very good manager, I have to say they are big favourites to go all the way and win the treble.
"They probably deserve it, but it is another two games where they have to be 110 per cent focused.
"They have to do all the good things they have done during the season and not complicate things.
"You have to play the football and right now that is probably going to be enough to win the treble, but there is still a very tricky game at the weekend.
"There is a lot of similarities to when we won the treble, our team won it early and this team won it earlier than we did.
"I don't think Brendan will have to motivate the players because they know what's at stake.
"A treble is something that won't happen that often.
"So I think the players will be so focused, but on the day you might come up against an opponent who does all the right things and tactically are playing out of their skins.
"So you can never ever be sure and take your eyes off the ball."
