McDonald made 203 appearances for Newcastle, scoring 28 goals, between 1982/88 and was Sam Allardyce's right-hand man at Bolton.
No Skeleton's In Ex-Toon Player's Cupboard
Carlisle owner Fred Story dismissed McDonald on Monday, just one game into the new season.
McDonald had presided over a 1-1 draw at Walsall on the opening day of the campaign after an impressive first season at Brunton Park.
The club revealed they had lost confidence in the manager and Story is adamant there are no underlying motives behind the decision.
Story: "There's nothing untoward in this. I like Neil as a person, but I've discussed it with the board and it is not a knee-jerk reaction.
"I informed Neil and it's fair to say he wasn't expecting it. But this isn't a personal or a disciplinary issue. There are no skeletons in the cupboard."
Neil started with Wallsend Boys Club like Beardsley and Shearer. He went to Carlisle and United paid £5,000 for him in August 1982.
Made his debut aged 16 and 326 days (v Barnsley), a record at that time. Went to Everton in July 1988.