Semien will become the second star and fourth free agent added by the Blue Jays during a slow offseason amid the coronavirus pandemic.
Toronto gave outfielder George Springer a $150 million, six-year deal. Toronto also agreed to one-year contracts with right-handers Kirby Yates ($5.5 million) and Tyler Chatwood ($3 million) and re-signed left-hander Robbie Ray to an $8 million, one-year contract.
Coming off a career year in 2019, Semien struggled in 2020 while dealing with a rib injury, as the shortstop hit just .223 with 7 home runs, 28 runs, 23 RBIs and 4 stolen bases for the Oakland Athletics. His production was down largely due to his strikeouts being up, as he fanned on 21.2% of his plate appearances.
It was a different story for Semien in 2019, when he finished third in AL MVP voting after posting personal bests with 33 home runs, 92 RBIs and a .285 batting average while playing in all 162 games. His WAR (8.9) was third in the majors that season, and he parlayed that into a one-year, $13 million deal -- more than double his contract after earning $5.9 million in 2018. He earned $4,814,815 in prorated pay for 2020.
Semien was tied for 190th among batters in WAR in 2020, with 0.5. Even with the decline in 2020, he is one of just six hitters to account for at least 9.0 WAR in the past two seasons combined.
Semien's 151 runs scored since the start of the 2019 season rank second among all American League players, and his 100 extra-base hits rank fifth.
In eight MLB seasons, Semien, who is above average when it comes to base running, has a .254 batting average with 115 home runs, 380 RBIs, 467 runs scored and 66 stolen bases -- but with 731 strikeouts in 3,266 at-bats -- for the Chicago White Sox and A's.
Toronto went 32-28 during the pandemic-shortened 2020 season, finishing third in the AL East behind the Tampa Bay Rays and New York Yankees and qualifying for the expanded postseason despite behind forced to play home games in Buffalo, New York, due to Canadian government restrictions on travel. The Blue Jays were swept in two games by the AL champion Rays in a first-round series.
Toronto has an emerging young core and is adding major contracts, while younger players such as Bo Bichette and Vladimir Guerrero Jr. have relatively low salaries because they remain shy of eligibility for arbitration.
It is not clear where the Blue Jays will play home games when the 2021 season starts.
ESPN Stats & Information and The Associated Press contributed to this report.