Casas suffered the injury while running to first after hitting a slow roller up the first-base line in the second inning of Boston's 6-1 win over the Minnesota Twins on Friday. He fell awkwardly and was carted off the field before he was eventually hospitalized.

Boston Red Sox first baseman Triston Casas suffered a ruptured tendon in his left knee and is out for the remainder of the season.

Last year, to its detriment, Boston put together a patchwork platoon to replace Casas. This time around, the franchise needs to act fast.