Gunnar Hoglund: Everything you need to know

Hoglund (knee/back) has begun a throwing progression, Martin Gallegos of MLB.com reports. Hoglund missed all of spring training and the start of the season due to a right knee sprain and a back injury. He's starting his throwing program from scratch, so it's going to take the right-hander a long time before he's cleared to pitch in games.

Hoglund received a PRP injection for his back this past Thursday, Martin Gallegos of MLB.com reports. Hoglund sustained both a right knee sprain and a lumbar spine strain during spring training, but it is the latter injury that has caused the most issues for the 26-year-old right-hander. He was transferred to the 60-day IL on April 7, and while the PRP injection should help with his recovery, the Athletics have not provided a clear timeline for Hoglund's return.

The Athletics transferred Hoglund (back) to the 60-day injured list Tuesday. The transaction frees a spot on the 40-man roster for the addition of Joel Kuhnel. Hoglund is recovering from a lumbar spine strain and it's unclear how far along he is in his rehab. He is now ineligible to return before late May.