The Florida Marlins and Detroit Tigers have agreed in principle on a trade that will send

Miguel Cabrera and Dontrelle Willis to Detroit for key prospects, sources told ESPN's Peter Gammons on Tuesday.

The Tigers would send outfielder Cameron Maybin, pitcher Andrew Miller, catcher Mike Rabelo and minor league pitchers Eulogio De La Cruz, Dallas Trahern and Burke Badenhop to the Marlins.

The deal is expected to be announced Tuesday night when the physicals and paperwork are completed.

"It's very serious, but nothing is finalized yet because some

issues need to get worked out," Tigers manager Jim Leyland told

The Associated Press.

Miller was Detroit's top pick in the 2006 draft and went 5-5 in 13 starts after being called up last summer. Maybin was the Tigers' first pick in 2005 and shot through the farm system, hitting .143 in 24 major league games, Rabelo batted .256 in 51 games, and 23-year-old De La Cruz appeared in six games for the Tigers, hitting 100 mph on the radar gun.

Willis was on vacation when he heard the news.

"I'm in Mexico right now with my family. I'm kind of busy," he

told the AP.