The Mariners have placed Ketel Marte on the 15-day disabled list (retroactive to July 20) after the shortstop was diagnosed with mononucleosis yesterday, the club announced. Left-handed David Rollins was called up in a corresponding move. Luis Sardinas was already called up yesterday to provide infield depth, taking the roster spot left by the traded Mike Montgomery.
[Related: updated Mariners depth chart at Roster Resource]
Marte has been sidelined for much of the week with the illness, leaving utilityman Shawn O’Malley making regular starts at short, and he’ll split time with Sardinas until Marte is healthy. A return date, however, is unknown given the unpredictable status of the illness. Manager Scott Servais told reporters (including Gavin Day of the Seattle Times) that Marte had already lost six or seven pounds, so clearly once Marte is recovered, he’ll still need time to get his strength back.
The sickness is the latest setback within a tough season for the 22-year-old Marte, who entered the year as the Mariners’ starting shortstop and looking to build on a strong 2015 rookie year. Instead, Marte has already had one DL stint due to a sprained thumb and he has hit just .273/.299/.358 over 300 PA with subpar defensive metrics. As per Fangraphs’ WAR calculation, Marte has been worth exactly 0.0 wins, making him nothing more than a replacement-level player.
These struggles made the Mariners one of the few teams who could be looking for shortstop help at the deadline, even before Marte came down with mono. Zack Cozart, Eduardo Nunez or Jed Lowrie are a few of the everyday options the M’s could pursue, though I’d argue that Lowrie is an unlikely target due to his recent lack of shortstop action and his big price tag. Seattle entered today’s action with a 49-47 record, 5.5 games behind Texas in the AL West and 4.5 games behind Toronto for the last wild card slot.