The Red Devils came from behind to take the lead kind courtesy of Tom Heaton’s own goal and Victor Lindelof’s header, but Tyrone Mings equalized for the visitors.
Manchester United sit 9th on the Premier League table, having won just four games in their first 14 league matches.
Aston Villa were clearly the better team and the Norwegian coach believes his side did not deserve to beat Dean Smith’s men.
"First half it seemed like we couldn't get to grips with going one-nil down," the 46-year-old said in his post-match press conference.
"When you concede a goal as early as that at Old Trafford you've got plenty of time to get back into the game, but I felt we didn't deal with that particularly well and we were lucky to go in at half-time with one each.”
"The second half was good, we put pressure on them and created chances. They had a decent chance with Grealish, but we created loads of big ones that could have won this game.”
“Overall, though, I don't think we deserved to - especially after the first half.”
"We are a young team. I don't want to use that as an excuse because we are Man United and we want to get a run together.”
“As soon as we get a run of three or four games together here now, that's what we need. That's what these boys need, I feel.”
"We just have to make sure we do everything right now until Wednesday because it's a short turnaround."