Several big name starting pitchers have already been on the move this offseason, and according to several rumors, the Seattle Mariners have been open to potentially trading their ace starting pitcher Luis Castillo.

With Sean Manaea (Mets) and Walker Buehler (Red Sox) signing in the last 24 hours, the list of potential trade partners for the Mariners is shrinking.

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.

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

Starting pitching remains at a premium this offseason, and as we enter the middle of December, the trade market is red-hot at the moment after several major trades went down this past weekend.

The Seattle Mariners entered the offseason with clear needs to address. Yet another whiff at second base has left them looking for almost an entirely new infield.

Per a recent report, the Boston Red Sox offered a second player to the Seattle Mariners that killed a potential trade involving Luis Castillo and Triston Casas.