Unfazed by the switch, Carl's excellent positional play and superb range of passing have been an integral part of the Hammers engine room since he signed from Bournemouth for £250,000 in August.
But the Welsh international actually made most of his 220 appearances for the Cherries as a centre-half and revelled in the deeper role against the Hornets.
"It was a different experience for me last weekend," he explained, "but I've played a lot of games at centre-half and it's a position I enjoy playing in.
"I thought we played well against Watford, and even when we found ourselves two goals down, no one thought that we couldn't come back to win. It was an excellent team performance and we'll need more of the same against Sunderland tomorrow."
However, Carl may not be able to show quite so much of those defensive attributes, as he may be asked to move back into the centre of midfield to cover for Nigel Reo-Coker, who will be missing through suspension. Typically, Carl takes the possibility in his stride.
"I'm happy to just do a job for the team," he said, "and I'm not really worried about where I'm playing.
"I feel comfortable whether it's midfield or defence to be honest. I've got plenty of experience filling both those positions and I know how to adjust my game to fit in to either defence or midfield.
"Nigel will certainly be a big loss for us at Sunderland, but if Alan Pardew wants me to move back to midfield I'd be more than happy to do so."
The Hammers boss is certainly full of praise for the former Bournemouth trainee, who worked with first-team coach Peter Grant at the Cherries.
"Carl has done an excellent job for us this season," added Pards. "Against Watford I felt that we would need to keep the ball at the back, and Carl's distribution was first-class during the game.
"His passing is superb, whether from defence or midfield, and he's a reassuring influence in the team. I still think Carl's best position is probably centre-midfield, but that does not take anything away from his defensive qualities, which he proved to be very strong last weekend.
"With his ability to keep the ball well and play telling passes, Carl will be an important player for us again at Sunderland."