The Red Devils legend is delighted with the arrivals of Nemanja Matic and Romelu Lukaku.
Both had good games in the 4-0 demolition of West Ham at the weekend with Lukaku grabbing a brace.
But it is Matic in particular who has impressed the ex-United captain.
He thinks the Serbian could be the long-term replacement for Old Trafford hero Michael Carrick.
Antonio Valencia sits down as Nemanja Matic picks up the ball
“To have signed Matic was a masterstroke for me”
Robson told talkSPORT: “It is one of those where you don’t get carried away by the one performance.
“But you look at the squad depth and we have got power and pace as well as the quality.
“Two of the signings have been terrific again to go with the signings we had last tear.
“Lukaku and Matic. Matic was terrific at the weekend.
“Everyone has said who is going to replace Michael Carrick. It’s great we still have Michael at the club.
“But to have signed Matic was a masterstroke for me.
“The signings there at the weekend were brilliant. He’s going to be a great player for Manchester United over the next few years and that gives us a real chance.”