From Alex Speier (Iglesias' presence matters):
For most of the year, the Red Sox infield has been the most porous in baseball. Through Sept. 9, they had allowed a .274 average on ground balls, easily the worst in the game and far worse, in the estimation of Statcast based on the type of contact, than the .245 expected average on such balls.
Since Xander Bogaerts returned from the COVID-19-related injured list Sept. 10, allowing the Sox to move José Iglesias to second base, they have allowed a middle-of-the-pack .252 average on grounders (with a .241 expected average). Meanwhile, double plays — which had gone missing in August — have again become routine, with the Sox turning 11 in the last 10 games.