The two clubs meet on Saturday in the FA Cup final.
"He's come in and done a great job – that's all you can say," said Carragher of Di Matteo. "At the moment he seems to be getting everything right.
"They've got great players and they've had a great side for a long time now, always competing for trophies.
"We've had some big battles with Chelsea over the years, some big games.
"Yes, they're on form. Their performance in Barcelona, we all watched that. You can only take your hat off to them.
"They've achieved something as a club and as players that they'll all remember, but it's a different game now and we're desperate to win."