Hernández and Osich were Boston's only two non-tendered players on Monday. By re-signing them, the Red Sox's 40-man roster is now at 36 players.
The new deals for Hernández and Osich are split contracts, offering Boston more flexibility.
Hernandez will make $650,000 for the Major League portion of his contract. Osich, meanwhile, will earn an $850,000 salary for the MLB portion of his deal.
Both players are considered depth options for the club.
There’s a chance Hernández could earn more playing time at second base with a strong showing in Spring Training. That position is currently wide open.
Osich will try to earn a spot as a lefty out of the bullpen, though it could be more challenging given the new rule this season that relievers must face a minimum of three batters.
For Hernández, the 2019 season was satisfying because he was able to return to action after missing most of the last two seasons with left shoulder woes. The 27-year-old had a walk-off single against the White Sox on June 25. In 61 games, he slashed .250/.279/.338 with two homers.
Boston selected Osich off waivers from Chicago on Oct. 31. He owns a 4.88 ERA over 217 career appearances at the MLB level, including a 4.66 mark in 57 appearances for the White Sox in 2019. The 31-year-old was a member of the Giants from 2015-18.