Carrick saw his start to the season hampered by injuries, but he has returned to the first team and helped the Red Devils win six of their last seven games with a 1-1 draw against Aston Villa the only blot on their copybook.
The 33-year-old has also been named as vice-captain to Wayne Rooney, underlining his importance to Louis van Gaal, and Ferguson is convinced he is the most effective midfielder in England.
“I think Michael's the best central midfielder in English football,” the legendary former United manager told BT Sport. “I think he's the best English player in the game.”
Carrick has been joined on the treatment table by the likes of Marco Rojo, Daley Blind and Angel Di Maria this season, and Ferguson has warned the rest of the Premier League that United will be a force to be reckoned with when Van Gaal has a fully fit squad to choose from.
“I don't know how Louis van Gaal can expect to get the best results with the injuries he's had," Ferguson continued.
“When he gets the best players back, you watch United go - because he's a great coach, he will do well.
“I'm not interested with what is happening with the players he's brought in, as that will take time.
“When I brought in Patrice Evra and Nemanja Vidic in the January of the same year, they were all over the place. They took five months to get used to playing for Manchester United - the culture and the history of the club. These new players will be exactly same.”
Ferguson believes United still have a raft of world-class players in their ranks, and singled out David De Gea for particular praise after his fine recent form.
“They have still got great players,” added the Scot.
“The World Cup has maybe taken a little bit out of Robin van Persie, but you watch him in the second half of the season. He will be fine.
“Rooney is back flying and he will always get you a goal. Having a goalscorer in your team is always an advantage.
“The one that is most pleasing to me is David De Gea. When we bought him as a kid he was really skinny but he had ability. He has special talents and he is showing that now and I'm really pleased for the kid.
“When we get those players back, we will be fine.”