LOS ANGELES -- All along, everyone thought it would be the hip.
Instead, it is the bottom of Mike Napoli's left foot that poses the greatest threat to his ability to play regularly in the season's final 32 games, and by extension, be a force in the middle of the Boston Red Sox lineup as they try to hold off the Tampa Bay Rays in the final weeks of the season.
Napoli is suffering the effects of plantar fasciitis, an odd-sounding condition whose name, like the innocuous-sounding "concussion," offers no clue to how debilitating it can be.
The plantar fascia is a thick fibrous band of tissue that starts at the heel bone and extends along the sole of the foot toward the toes. When it becomes inflamed, it can become extremely painful.
Here's how Morgan Valley, a former guard on the University of Connecticut women's basketball team that won the national championship in 2002, described the condition to Jeff Pearlman of SI.com.
"Sort of the same as someone picking up my foot, grabbing a thick piece of wood and slamming it repeatedly into my sole," she said. "It's a uniquely terrible injury."
Napoli said the condition first flared on him when the team was in Anaheim on the weekend of July 5-7. In 32 games since the Sox played the Angels, Napoli has posted a slash line of .207/.313/.432/.745, with twice as many strikeouts (47) as hits (23) in 128 plate appearances.
Until Saturday, Napoli had not been in the starting lineup since he aggravated the condition sliding into second on a double against the Yankees on Aug. 16. He has made just three plate appearances since then, entering in the eighth inning of two games against the Giants in San Francisco last week. Saturday, he singled in a run in his first plate appearance.
He returned to the lineup Saturday, playing first base and batting cleanup against Dodgers left-hander Hyun-Jin Ryu, after taking a cortisone injection in his foot.
"I got to play a couple of innings here and there the past week, and it's felt all right," he said Saturday morning. "The reason why I got the injection was because I was at a point where it was bothering me pretty good. I'm going to go into treatment for every day, like I've been, and try to take care of it as best as I possibly can.
"I'm just going to have to grind through it and play through some pain -- which I have been already."
It's an open question, though, of how long Napoli will be able to play by simply willing himself to do so. Earlier this week, the Angels shut down their star slugger, first baseman Albert Pujols for the rest of the season after he tried playing through the condition.
"Everyone is different," Napoli said when asked if he found the Pujols' situation worrisome. "Everyone can handle things differently. I don't know what was going on in his situation. Only time will tell. We'll see what happens. I'm going to try to stay out on the field and deal with it as much as possible."
Napoli insisted the condition has not affected him at the plate.
"I don't feel it one bit hitting," the Red Sox first baseman said. "That has nothing to do with anything. Running is definitely the worst part of it -- sometimes in the field, going to first base."
But Pujols also said his condition did not affect his hitting, either, yet he put up what were by far the worst numbers of his career: 258, 17 home runs and 64 RBIs. Didn't affect his hitting? Pujols told USA Today this week that when he awoke in the morning, he was in so much pain he didn't want to get out of bed to use the bathroom. He said he has had the condition in varying degrees for nine years.
Part of what makes the condition so insidious is there is no prescribed course of treatment guaranteed to work. Typically, it is a slow-healing injury, one for which extended rest is often recommended. For Napoli, that's not an option.
Nonsteroidal anti-inflammatories, like ibuprofen, may help. Physical therapy, night splints, orthotics, are all options. Multiple cortisone shots are not recommended because it could weaken the plantar fascia and cause it to rupture, although Napoli said he has heard that "popping it" might ultimately be a positive outcome.
Rays third baseman Evan Longoria reported a flareup of plantar fasciitis in mid-June. In his last 55 games entering play Saturday, Longoria was batting .221.
Manager John Farrell admitted to being uncertain about how much Napoli will be able to play the rest of the way, noting that there will be times he'll probably have to use Mike Carp or Daniel Nava at first base. He also acknowledged that Will Middlebrooks took some ground balls at first during the last homestand, but with Middlebrooks playing so well at third, Farrell said he was reluctant to make a change. He did not rule it out, however, and with 20-year-old Xander Bogaerts here, that option would appear likely to be on the table if Napoli's condition worsens again.
For his part, Napoli thinks he can grind it out.
"Yeah, I feel like I can be in there every day," he said. "I thought that before and I was doing it. some days are better than others but I think I’m pretty tough to be able to grind through some stuff. I’m just going to go one day at a time."