SAN DIEGO -- Japanese two-way sensation Shohei Ohtani of the Los Angeles Angels has resumed throwing bullpen sessions, and new pitching coach Mickey Callaway is impressed.

Ohtani got back on the mound last week and pitched a bullpen in front of Callaway in Anaheim on Monday, general manager Billy Eppler told reporters at the winter meetings.

Eppler shared the contents of a text message he received from Callaway: "Shohei looked pretty darn good today. He does it very easy and we worked on some things in regards to his tempo. Everything synced up very well. I like this guy."

Eppler said he didn't know how many pitches Ohtani threw Monday but that he threw 25 during one session last week.

Ohtani had Tommy John surgery after the 2018 season and didn't pitch in any games in 2019. He did start a throwing program last season, with bullpen sessions before certain games. He had season-ending surgery on his left knee in mid-September.

Ohtani was used as the designated hitter last season, batting .286 with 18 home runs and 62 RBIs in 425 plate appearances.

He was 4-2 with a 3.31 ERA in 10 starts as a rookie in 2018. He also hit .285 with 22 home runs and and 61 RBIs.