Lampard, who has started only one of the last four games, appears to be one of the players most at risk for his place following Mata's arrival but he welcomes the impact he has made.
He said: "It is nice to introduce a different sort of player, someone who can flit into the hole and then be out wide again. It's a great thing for the fans to see and a great option if the game is a bit stale. It might create a bit of magic.
"To see Mata delivering early on and also flitting inside - playing the one-twos and looking so sharp - that kind of alternative will be great to see."