The Arsenal hero was impressed with the Red Devils in their 4-0 win against West Ham last weekend.
A brace from Romelu Lukaku as well as goals from Anthony Martial and Paul Pogba have United the three points at Old Trafford.
“Give them their credit, last year they couldn’t win a game at Old Trafford and everybody was having a go,” Henry said on Sky Sports.
“On the day, yes it was a great game, but now it’s a long way to go before you can get carried away and whether they can win the title or not, but signs were there.
Kevin Wimmer from Tottenham to West Brom (2/5)
“You can’t get carried away on whether they can win the title or not, but signs were there”
Arsenal hero Thierry Henry
“What impressed me the most is their capability of going and getting the ball back high, instead of being passive.
“You saw that on the goal when Matic went to get the ball from Obiang.
“Rashford, with the pace that he has and the finishing of Lukaku, but everybody is talking about their goals, but they didn’t concede any.
“That is important, Eric Bailly was massive on Sunday.”
United are currently in action against Swansea in the Premier League at the Liberty Stadium.