"Best of luck to the FINAL 4 contestants!!" the pop superstar, 31, tweeted on Monday morning. "Congrats making it to #TheVoice finale! I have much love for all of you!! Good luck today :) :)"
36-year-old Lucca -- who once costarred with Aguilera, Britney Spears, Justin Timberlake and others on The Mickey Mouse Club -- is the remaining singer from Adam Levine's team; Paul, 32, represents Blake Shelton's group, and Simms, 26, is Cee-Lo Green's choice.