 Lehtonen, appeared in 60 games with Jokerit during the 2019–20 season and registered 49 points (17 goals, 32 assists), which led all KHL defencemen.He represented Jokerit at the 2020 KHL All-Star Game and was named KHL Defenceman of the Month in three consecutive months from November to January.He had a goal and three assists in six KHL playoff games prior to the cancellation of the season.