Gonzalez said the neck was bothering him even before Thursday's loss to the Kansas City Royals.
"I played through it, it wasn't good,'' he said. "It got worse as the game went on. Yesterday I got lucky with a hit. Pitchers just left pitches up. I wasn't able to turn my neck. I had to hit open, adjust my stance. It wasn't going to be good for me to try and play tonight.''
Gonzalez missed his first game on July 6 with what the team said was a similar condition.
"It wasn't the neck,'' he said. "I don't know why they said it was the neck. I had it last year. Just something I got to figure out what causes that side of my neck to grab. I wake up one day and I can't move it. It might be just stress from swinging, throwing, moving around.
"I should play tomorrow. It got a lot better as the day went on. I got it worked on. I can't swing normal, I can't look at the pitcher from my normal stance. I've got to open up. When you got to do those kinds of things, it's not working.''
Gonzalez, who was in the original lineup Friday and was a late scratch, has started 102 of the team's first 104 games.
He came into the night leading the majors in hitting with a .352 average, in RBIs with 87, and hits with 148. He also had an eight-game hitting streak, one in which he was batting .529 (18-for-34).
But he had just one extra-base hit in the current streak, and in 25 games since June 26 he has hit just one home run with five doubles. That's after hitting 15 home runs in a span of 48 games from May 3 to June 25.
But Gonzalez said the neck hadn't bothered him before Thursday, so that evidently isn't a factor in the drop in his power.
Gordon Edes covers the Red Sox for ESPNBoston.com.