It hasn't been a good start to the season for the Boston Red Sox by any means, but one might shudder to think about where the team would be without Willson Contreras. After arriving in a December trade with the St. Louis Cardinals, Contreras has hit well even when the entire lineup around him has gone into a stupor. He drove in his team-leading 23rd RBI on Wednesday to help Boston finish off a sweep of the Detroit Tigers, and he also sported eight home runs and a 143 OPS+. All of that context made it doubly scary when Contreras winced and flexed his hand on several swings during his last at-bat of the night, a swinging strikeout, also prompting a visit from the athletic trainer and interim manager Chad Tracy. That hand will be something to keep an eye on with Willson Contreras. Hopefully a good sign that it didn't seem to be bothering him once he got to the dugout.…