The Hammers' record signing hasn't kicked a ball in 2014/15 after undergoing ankle surgery in the summer, but is targeting a December return for Sam Allardyce's side.
Seven points from their last four league games have propelled the east London club to eighth in the standings, with new signings Mauro Zarate, Enner Valencia and Diafra Sakho all opening their accounts in a more attack-minded team.
Carroll believes the added strength in depth has played in a key part in their productive opening, and means they go to Old Trafford on Saturday - a venue they have lost at on 10 of their last 11 visits - full of confidence.
Speaking to FourFourTwo and others at the launch of West Ham's 'Club London', he said: "We're playing great football, it's great to see. I was over the moon with the result against Liverpool and against Hull it was a good game as well.
"We've got some great players. The signings have been fantastic; the whole outlook of the team is just a lot stronger. Even in training you see that there's more bodies there, people fighting for places and it's a great one to be involved in.
"Cheikhou [Kouyate] in the middle has been brilliant. He never stops running and gives it everything. He's his own person, I can't see anyone like him; he runs, he tackles - I think he's the best signing we've got."
The Hammers are due to move into their new 54,000 home in 2016 with the increased capacity and hospitality set to boost the club's revenue streams; something Carroll says can help the club achieve European qualification.
"I spoke to Sam before I signed and he told me about the plans going forward," he said. "He actually mentioned the top six and getting into Europe.
"You always want to play at the best level; the Premier League is one of the best in the world. It's what I've always wanted.
"We're moving to a bigger and better stadium, and it's all looking good. Much bigger and better. This club is only going one way, and that's forward."
West Ham have launched Club London, offering supporters stunning VIP areas at their new home located in the heart of Queen Elizabeth Olympic Park.
