As embarrassing moments go, it isn't likely to ever get any worse for Pablo Sandoval than his previous trip to Canada, when his belt buckle exploded on a swing during a game last April.

Compared to that, what happened here Wednesday night barely registers on the scale of public humiliation.

But Sandoval's errant throw on a routine grounder did open the door to a three-run second inning for the Toronto Blue Jays and a 3-0 outcome that snapped the Boston Red Sox's four-game winning streak. It marked Sandoval's third error in 12 games, tied for most in the majors among third basemen, and raised the same old questions about whether his defense is reliable enough to keep him in the lineup every day.

For all the reasons Sandoval lost his job before last season, his defense ranked high on the list. The Red Sox believed his range had been limited by his excessive weight, and his throws were less accurate than usual, leaving manager John Farrell to sit him in favor of upstart Travis Shaw, who was a more consistent defender even though he had played first base for most of the previous few seasons in the minor leagues.

Since then, Sandoval has had surgery to repair a torn labrum in his throwing shoulder and dropped about 40 pounds. And after the Red Sox in the offseason traded Shaw to the Milwaukee Brewers for reliever Tyler Thornburg and top prospect Yoan Moncada to the Chicago White Sox for ace Chris Sale, Sandoval reclaimed his position with a solid spring training.