But that issue has been resolved and the Frenchman is now set to begin his second spell as a manager in England after a successful time with Liverpool, where he won the FA Cup, League Cup and Uefa Cup Treble in 2001.
MacDonald has been in charge of the team since former boss
Martin O'Neill resigned
in August, taking control for the first six games of the season.
But the reserve team coach says he is now considering his options after losing out to Houllier for the manager's job.
"I put myself up for the job and once I did that I knew there might be disappointment," said MacDonald after Villa's 2-1 defeat at Stoke on Monday night.
"It took me long enough to decide and once I didn't get the job I was very disappointed.
"But the decision to go back and work with the reserves when Mr Houllier came in was totally down to me wanting to re-evaluate and see what I can - or want - to do.
Villa have lost three games, won two and drawn one under MacDonald
"I may need to rethink what I may want to do. I may want to be a manager.
"Some people might think I will make a good manager, some people might not - but I need to know for myself.
"Maybe I've gained a bit of confidence [as a result of his managerial duties] but I can't say it's changed me in any way."
Houllier is keen to appoint former Coventry and Leeds manager
Gary McAllister as his assistant
after ex-Liverpool stars Phil Thompson and Dietmar Hamann as well as MacDonald turned down the opportunity.
And MacDonald admits there was never any realistic chance of him becoming Houllier's assistant once the manager's job had passed him by.
"I had always thought that when I did not get the [manager's] job that I wasn't going to do it [assistant]," he said on Monday.
"I think Mr Houllier is already in the process of getting some of his backroom staff but if I am asked to do something by the Villa manager that is what I will do because I work for Aston Villa football club, I work for Aston Villa's manager.
"He asked me on Friday if I would do those things (prepare the team for Stoke and Bolton) and I have no problem at all.
"That will still happen when I go back to the reserves. If he asks me to go out scouting I'll do some scouting, if he asks me to go and help with the first team I'll help out - until I decide what I want to do."
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