The Pirates announced today that shortstop Jordy Mercer has been placed on the disabled list with a sprained medial collateral ligament in his left knee as well as a lower leg contusion. The injury, which comes with a recovery time of approximately six weeks, per the team, was sustained on a controversial takeout slide (video link) by Brewers center fielder Carlos Gomez.

To fill Mercer’s spot on the roster, the Pirates selected the contract of Brent Morel. First baseman Corey Hart was transferred to the disabled list to make room for Morel on the 40-man roster.

The loss of Mercer further depletes Pittsburgh’s infield depth. Starting third baseman Josh Harrison is already on the shelf for up to six more weeks with a torn ligament in his thumb, which has caused offseason pickup Jung Ho Kang to shift into a full-time role at the hot corner. Presumably, Kang will now take over as the club’s shortstop, with Morel playing third base. As Travis Sawchik of the Pittsburgh Tribune-Review tweets, acquiring a right field upgrade probably becomes a luxury for the Pirates, with the focus shifting to a third base upgrade.

The list of third base candidates believed to be available is relatively limited, with Aramis Ramirez from Milwaukee standing out as the most oft-mentioned possibility. Atlanta’s Chris Johnson, of course, is available, though his contract has stood as a significant road block. His Braves teammate, Kelly Johnson, is a versatile bat that could potentially play some third base in the short term. Utility options such as Cliff Pennington and Clint Barmes, who was with the Pirates from 2012-14, could potentially be acquired to step in at shortstop, with Kang remaining at third base.