A person familiar with the deal tells The Associated Press that the ace left-hander and reliever Mark Lowe have been traded to the AL West-leading Rangers for first baseman Justin Smoak and three minor leaguers.
The person requested anonymity because an official announcement had yet to be made. The Rangers and Mariners both scheduled press conferences for later Friday.
It was the third trade in less than a year for Lee, who can become a free agent after this season. The 2008 AL Cy Young Award winner went 8-3 with a 2.34 ERA in 13 starts for the Mariners, who acquired him from the Philadelphia Phillies in December.
Smoak is one of the top prospects in the majors, but hit .209 in 70 games for Texas this season.