Giggs had a short stint as caretaker after the sacking of David Moyes in 2014.
He told The Greatest Game podcast: “If I'm honest, I wanted the job [after Moyes was sacked]. But I wasn't ready.
“There is a trend at the moment with younger coaches who have played for the club getting the jobs.
“At that time there was still a lot of the older managers coming in. They were seen as safe. I wanted the job when I had those four games, but I wasn't ready.
“I was definitely ready after Louis [was sacked] and I wanted the job but I was nowhere near it.
“I'm more ready now but I think that's gone now, I think the chance has gone now.
“I think it's gone, I've done it. I'm happy with the job I've got. I can't see that coming around again."