The 39-year-old, who recently guest mentored the singing reality show, said Sanchez is by far his favourite contestant this season, Daily Star reported.
"I know I shouldn't be saying this, but I kind of want her to get voted off so I can sign her. She's beyond the talent that's supposed to be there. I think she's overqualified, I really do.
"And she's only 16. I've been around a lot of superstars. I haven't seen anyone at that age sing like that," he said.