O’Neill handed Reo-Coker the captaincy in the 5-1 win over Bolton at the weekend.
Reo-Coker was given his first start since his training ground bust-up with the former Celtic and Leicester manager in September.
“I’m too old to start holding grudges now,” said O’Neill.
“Perhaps when I was at Nigel’s age I probably would have done. But I’m too old and for the benefit of the team it’s not that important.
“Nigel and myself had a bit of a spat. It’s over and gone with, it was quite some time ago.
“What will be, will be, but I just want players to come in here and give everything for this football club and try and win games in this league.
“The opportunity arose to put him into the side and I felt if he’s going into the side he might as well burden himself with the extra responsibility as captain as well. I thought he acquitted himself really well.”
