Red Sox starting pitcher Walker Buehler is 4-1 in six starts in his first season with Boston. David Richard/Associated Press

The Boston Red Sox placed right-handed starter Walker Buehler on the 15-day injured list with right shoulder bursitis Friday, one day after the team sent him from Toronto to Boston to undergo tests.

Buehler had been scheduled to start Friday as the Red Sox opened a three-game series against the Minnesota Twins at Fenway Park. The reason for the tests stem from his inability to bounce back after his last start which was last Saturday when the 30-year-old allowed three runs and seven hits in six innings to beat Cleveland, his third straight winning start.

Buehler is 4-1 with a 4.28 ERA in his six starts since signing a one-year, $21.05 million contract with the Red Sox this past offseason. He spent the first seven years of his MLB career with the Los Angeles Dodgers, winning two World Series.

Taking Buehler’s place on Boston’s roster is right-hander Hunter Dobbins, who was called up from Triple-A Worcester.

Also Friday, the Red Sox reinstated catcher Connor Wong and optioned Blake Sabol to Worcester. Wong was in Friday’s lineup, hitting seventh. He landed on the 10-day IL on April 8 with a left pinky fracture.

During the game, Red Sox first baseman Triston Casas was carried off the field on a stretcher after suffering an apparent lower-body injury.

Casas sent a slow roller up the first-base line that Twins starter Joe Ryan bobbled before his underhand throw to first baseman Ty France. Casas was ruled safe as Ryan was charged with an error, though it was clear something was wrong with Casas, who fell awkwardly near first base.