Interest in Castillo increased significantly after the New York Yankees signed free-agent lefty Max Fried to an eight-year, $218 million contract, a Mariners source said. Castillo, 32, is owed less than one third that amount — $68.25 million over the next three years.

Seattle Mariners General Manager Justin Hollander had high praise for Luis Castillo in an appearance on MLB Network Radio.

The Mariners have an opportunity to use some of their excellent starting pitching depth to improve the offense but the team has doubts.