Walsh and Kerry captain Peter Crowley were cited by the CCC for involvement in a fracas that developed late in the Allianz FL clash with Mayo.
Tom Parsons received a straight red after the melee, but the match official took no further action.
However, both Kerry players were later charged with striking and granted a personal hearing on Thursday night.
Crowley won his appeal and will lead Kerry out against Monaghan but Walsh will serve a one-match ban.
Fitzmaurice is not impressed with the 11th hour process: “Obviously, Donnchadh is suspended, although we had him chosen on the team. It came very late in the day as the Mayo player was dealt with last week.
“But nothing surprises at this stage. I would be interested to see how consistently they apply the rules throughout the season. I think the CCCC will have a busy year.”
Before Walsh’s late ineligibility, Kerry had made three changes from the side that started against Mayo, with Brendan Kealy starting in goal instead of Brian Kelly, Shane Enright returning after concussion with Jonathon Lyne moving to attack and James O’Donoghue replacing Legion team-mate Conor Keane.
Kerry’s subs bench is also strengthened with the return of Stephen O’Brien, Bryan Sheehan and Anthony Maher. Kerry will decide later who replaces Walsh on the starting 15, with Barry John Keane or Adrian Spillane the leading contenders.
Fitzmaurice rued Kerry’s indiscipline and sloppiness against Mayo and wants no repeat against Monaghan.
“We conceded 0-9 from frees, we created six goalscoring chances and we took one.
“It’s important that we iron out those kinks.”
Fitzmaurice is expecting another tough contest tomorrow but is not yet in the business of calculating Kerry’s point requirements.
“There are five games in the next six weeks so there is a lot of football to be played, a lot of points up for grabs but as always we are just looking at Sunday’s game, try to get something out of it and move on after that.
“I think it is afterwards you look into the significance of things. It’s a game we need to win after losing the last day and that’s about the size of it.
“They are a good side as they proved two years ago when they came to Tralee and beat us.
“They have improved since 2015, with some new players that they have introduced. They have done well in the league so far this year and young players like Conor McCarthy, Thomas Kerr, and Gavin Doogan have been very impressive.
“They are constantly evolving like ourselves and we know that they have some dangerous forwards, they are well set up and they are very hard to break down.
“They have won a couple of Ulster championships so I don’t think it will come as that much of a surprise to anyone as to how competitive they will be on Sunday.”
And Fitzmaurice will be particularly watchful of the threat posed by Conor McManus.
“He is a huge threat and we cannot afford to give away as many frees as we did against Mayo, close to goal and even further out the field.
“Rory Beggan the keeper is capable of coming up the field and kicking long range frees as he did when he kicked a few bombs into the wind in that game two years ago in the Austin Stack Park.
“So those points are very important to them and of course Conor McManus is an exceptional player and freetaker so we cannot afford to be giving away cheap frees.
“We knew that straight away after the game on the Saturday night against Mayo so it is obviously something we need to improve on.”