The Twins added three prospects — pitchers Jordan Balazovic and Bailey Ober, and catcher Ben Rortvedt — to their 40-man roster Friday to protect them from Major League Baseball's Rule 5 draft.

Balazovic, 22, was on the Twins' practice squad last season in St. Paul after pitching in Class A in 2019, where he was 8-5 with a 2.69 ERA at Cedar Rapids and Fort Myers. He was a fifth-round pick in 2016 out of St. Martin Secondary in Mississauga, Ontario.

The hard-throwing righthander, who is 6-5 and 215 pounds, had 129 strikeouts in 92⅔ innings in 2019, starting 18 of his 19 appearances. A Canadian, Balazovic pitched for the World Team in the All-Star Futures Game in 2019 and is ranked as the Twins' fifth best prospect by Baseball America.

Ober, 25, pitched in rookie league, Class A and Class AA in 2019 and was 8-0 with a 069 ERA in 14 games. The righthanded starter is 6-foot-9 and weighs 260 pounds, and was a 12th round selection in 2017 from the College of Charleston.

He relies on control, not velocity, but still had 100 strikeouts in 78⅔ innings, starting 13 games. Ober's minor league numbers overall are outstanding — 17-3 with a 2.38 ERA in 181⅔ innings, with 223 strikeouts and a .94 WHIP in 34 games over three seasons.

Rortvedt was at Fort Myers and Class AA Pensacola in 2019 and hit .238 with seven home runs in 79 games. The 23-year-old, who was a nonroster invitee to spring training in 2020, was taken in the second round in 2016 from Verona (Wis.) High School.

The Rule 5 draft is on Dec. 10. Any eligible minor-leaguer (three years out of college or four years out of high school) who was not on a team's 40-man roster by 5 p.m. Friday can be chosen by another team, although the drafted player must remain on his new team's major league roster for the entire 2021 season or be offered back to his original franchise otherwise.

The Twins have 37 players — 19 pitchers, four catchers, six infielders and eight outfielders — on their 40-man roster. Players with guaranteed contracts include third baseman Josh Donaldson, pitcher Michael Pineda, right fielder Max Kepler, first baseman Mig­uel Sano, shortstop Jorge Polanco and pitcher Kenta Maeda.

Their arbitration-eligible players are left fielder Eddie Rosario, closer Taylor Rogers, starter Jose Berrios, center fielder Byron Buxton, relievers Tyler Duffey and Matt Wisler, and catcher Mitch Garver.

The team's free agents are designated hitter Nelson Cruz; utilitymen Ehire Adrianza and Marwin Gonzalez; catcher Alex Avila; and pitchers Jake Odorizzi, Sergio Romo, Rich Hill, Tyler Clippard and Trevor May.