Today's MLB Immaculate Grid features a crossover between the Oakland Athletics and the Boston Red Sox. Those teams don't have a lot in common, but they have had a few players cross the team lines.

Naturally, Bartolo Colon is usually a safe guess. In this case, he would be correct. The veteran pitcher was with both the Athletics (2012-2013) and the Red Sox (2008). At the time of writing, just 1% of players had used his name for this section of the grid.
MLB Immaculate Grid Answers August 23: Which Athletics players have also played for the Red Sox?
Here are some other answers for who was with the Red Sox and the Athletics:
- Yoenis Cespedes (2012-2014 with OAK, 2014 with BOS)
- Johnny Damon (2001 with OAK, 2002-2005 with BOS)
- Nomar Garciappara (2009 with OAK, 1996-2004 with BOS)
- Rickey Henderson (1979-1998 with OAK, 2002 with BOS)
- Rich Hill (2016 with OAK, 2010-2012 and 2015 and 2022 with BOS)
- Jon Lester (2014 with OAK, 2006-2014 with BOS)
Jose Canseco is another good answer. The controversial slugger was with the Athletics from 1985-1997. In 1995 and 1996, he took a brief hiatus from the team and joined the Red Sox.

Be sure to visit Baseball Reference. Their database knows every single player that ever played even a single game for the Athletics and Red Sox. That can and will help your rarity score.