Ole Gunnar Solskjaer accused Southampton midfielder Oriel Romeu of a "nasty" tackle on Mason Greenwood but refused to get embroiled in another VAR controversy.
Romeu appeared to stamp on Greenwood's ankle late in the first half of United's 2-2 draw with the Saints, but while the incident was looked at by VAR official Lee Mason, he didn't deem it worthy of a red card, or even tell referee Chris Kavanagh to consult the pitchside monitor, as officials are being encouraged to do for potential sending-off offences.
Greenwood was fortunate to escape injury for the rash challenge, which brought criticism from Sky Sports co-commentator Gary Neville.
Solskjaer was surprised Greenwood didn't hurt himself and accused Romeu of a bad challenge, but didn't want to be drawn on the effectiveness of VAR.
"I know my ankle would not take that challenge, it was a nasty one. We have said enough about VAR," he said.
After seeing a replay of the challenge on air, Neville said: "I do not like that. I think that’s a bad one. The ball’s gone, he’s tried to do him.
"I think he’s lucky there, Romeu. The ball’s gone, they can be leg breakers those ones."