What It Means:

This move was likely motivated by the depth issues that the Mariners have been forced to deal with in their starting rotation. Felix Hernandez, Wade Miley and Taijuan Walker have all been forced to miss time, so Lee could be presented with an opportunity to slide in and contribute right away.

A first round pick from the 2010 draft, the 24-year-old Lee owns a 4.89 ERA and 1.49 WHIP on the year with Triple-A Oklahoma City. He's fanning 6.96 batters per nine frames across 73 2/3 innings and owns a 7-5 record (13 starts).