To make room for Shaw, who got the start at first and batted eighth in Tuesday's game vs. the Marlins, on the 25-man roster, knuckleballer Steven Wright was optioned to Pawtucket following Sunday's game.
It's been a challenging season for Napoli, as his average has fallen to .192. The first baseman is doing his best to break out of a season-long slump, coming to the ballpark early and on off-days to work with hitting coach Chili Davis.
Napoli's goal in the batting cage and during batting practice is to get more on top of the ball and use the middle of the field.
"I think that's the frustrating part, where I feel so good. I'm healthy, I'm sleeping well. That's the frustrating part," said Napoli, who had facial surgery in the offseason to treat a severe case of sleep apnea. "I'm putting in work. I've probably put in more work this year than I ever have in my career, because I'm not tired. I don't know. I'm going to just keep grinding. When I get my opportunity, I'll try to make the best out of it."
On Sunday vs. the Astros, the Red Sox had designated hitter David Ortiz start at first base. It was the first time he started at the position in a non-Interleague contest since Aug. 5, 2006. Farrell said Ortiz continues to be an option.
"At some point, that work has to be put back on the field and have an opportunity to play itself out," Farrell said. "For the time being, we are giving him that chance to work through things."
Napoli is optimistic that the extra work he's putting in will pay off.
"I wake up every day thinking, 'Today is the day.' I'm a confident person. I've been doing this for a long time," Napoli said. "I know I'm one swing away from feeling what I need to feel."
Quinn Roberts is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.