Toronto is reportedly sending Boston $1.5 million in the deal.
Pearce has gone 23-for-79, including four home runs and 16 RBIs, in 26 appearances with the Blue Jays this season. Pearce has been primarily an outfielder on the defensive side of the ball but has also made several appearances at first base this season.
The 35-year-old has been with the Blue Jays since signing a two-year, $12.5-million contract in December 2016. The Red Sox will be the seventh team Pearce has suited up for in his 12-year MLB career.
Pearce was among the handful of pending free agents on the Blue Jays that many expected to be dealt before the end of the season.
Meanwhile, Espinal has spent the 2018 campaign playing high-A ball with the Salem Red Sox where he has hit .314 with seven home runs and 32 RBIs in 64 games. In fact, he was pulled early from Salem’s Thursday game against the Carolina Mudcats as the trade was being completed, which snapped the 15-game hitting streak he was riding.
The 23-year-old Dominican was selected by the Red Sox in the 10th round of the 2016 MLB Draft.