Williamson (shoulder) allowed two hits and one walk while striking out two over two innings for Triple-A Louisville on Tuesday.
Williamson got up to 31 pitches before rains came and forced a postponement of his third rehab start. The organization targeted 60 pitches for the rehabbing left-hander, who eventually completed two up-and-downs in the bullpen to reach 65 pitches, per MLB.com. Williamson will make at least one more start for the Bats on Sunday.