Red Sox trade former top prospect Marcelo Mayer to Giants: Will a change of scenery help?

The Boston Red Sox are sending young infielder Marcelo Mayer to the San Francisco Giants in exchange for left-handed reliever Erik Miller, the Athletic reports. 

The departure of Mayer out of Boston is a stunning one. The 23-year-old former No. 4 overall pick was not long ago one of the top prospects in baseball. Mayer, though, has thus failed to compete against pitching at the highest level. In 364 MLB plate appearances spread across this season and last, Mayer has a slash line of .223/.278/.346 with 24 walks against 84 strikeouts. Presently, he's on the injured list because of a stress reaction in his forearm. Mayer has been on the IL since late June. He goes to the Giants as a high-upside change-of-scenery candidate with just more than a full year of major-league service time. 

Miller, 28 and a former Stanford product, has thrived across a limited sample since converting to a bullpen role. Over the last two seasons, he's put up an ERA of 2.15 with 67 strikeouts and 36 unintentional walks in 62 ⅔ innings. He averages 97 mph with his sinker and fastball, and he has above a 50% whiff rate on his slider. Miller is under team control through the 2029 season.  

For the Red Sox, it's another buyer's move as they've barged back into contention and playoff position thanks to a 23-4 record since July 1. They entered deadline day coming off a road sweep of the two-time defending-champion Dodgers. Earlier on Monday, the Red Sox acquired catcher Adley Rutschman from the division rival Orioles.