Bieber (elbow) will make his first rehab start Saturday in the rookie-level Arizona Complex League, SI.com reports.
Bieber, who underwent Tommy John surgery April 12, 2024, has been throwing to hitters in Arizona since the start of May and is now ready to begin his rehab assignment. The veteran right-hander will need a lengthy ramp-up period, and it's possible his rehab will move up to a full-season affiliate after Saturday's outing.