Sources: Red Sox, Masataka Yoshida agree to 5-year deal

Why Fenway Park isn't an ideal fit for Masataka Yoshida (2:30)

Tristan H. Cockcroft breaks down why Masataka Yoshida can be a big-time performer, but Fenway Park doesn't favor his statistical outlook. (2:30)

Outfielder Masataka Yoshida and the Boston Red Sox agreed on a five-year, $90 million contract Wednesday, sources told ESPN, adding the most productive bat in Japan over the last two seasons to a quickly retooling Red Sox team.

Yoshida, 29, locked in a deal with the Red Sox on the first day he was eligible to sign after the Orix Buffaloes, the reigning Japan Series champion, posted him. A corner outfielder, Yoshida hit .335/.447/.561 with 21 home runs, 80 walks and just 41 strikeouts in 508 plate appearances this year.

Earlier in the day, Boston agreed to a two-year, $32 million contract with closer Kenley Jansen, bolstering a bullpen that was one of the worst in baseball last season. Yoshida is expected to have an even greater impact -- and the Red Sox paid a price higher than expected to secure him.

In addition to the $90 million due to Yoshida, the team will pay a $15.4 million posting fee to the Buffaloes, bringing the total outlay by Boston to $105.4 million. The posting system allows players under contract with foreign teams to sign with Major League Baseball club, with the MLB team paying a fee based on a percentage of the guaranteed salary.

Yoshida spent seven seasons with Orix, distinguishing himself as one of the best players in Japan. Over his career, he has batted .326/.419/.538 with just 307 strikeouts in 3,251 plate appearances. Minnesota Twins leadoff man Luis Arraez was the only player in MLB last year with a lower strikeout rate than Yoshida.