Matz had been shut down with what he called a strained flexor tendon in his throwing arm and Lugo had been shut down when it was discovered he had a slight tear in his UCL.
There is no timetable for either pitcher but both coming back healthy would go a long way for the Mets and their starting pitcher depth. Both would provide an immediate upgrade over current sixth starter Rafael Montero, who has allowed 24 base runners in 6.2 innings of work.
As a pitching staff on the whole, the Mets currently rank third in fWAR, second in FIP, and 10th in ERA. Their starting pitchers make up 2.2 of the 2.6 fWAR the Mets have accumulated. Their 2.2 fWAR is second in baseball among all starting staffs.
While their rotation is in a very good place, a lot could go wrong if one or more are out for an extended period of time. Lugo and Matz would help mitigate any injuries when they return from their own injuries.
With Zack Wheeler likely to hit his innings limit earlier than the Mets expected, the return of Matz and Lugo is all the more important.