Casas went 1-for-4 in his big-league debut Sunday in a 5-2 win over Texas.
Casas hit sixth and played first base in his first game in the majors. After flying out and grounding out in his first two at-bats, he recorded his first big-league hit, an infield single in the fifth inning. The 22-year-old posted a .273/.382/.481 slash line with 11 homers in 72 games for Triple-A Worcester before being promoted. With Bobby Dalbec optioned to Triple-A and Eric Hosmer (back) on the injured list, the rookie is likely to get the bulk of the opportunities at first in the near future.