Upton responded by going on a tear after that and finished with a .289 average to go along with 31 homers and 88 RBIs.
So far, 2012 has been a rough one for Upton, who had to battle through an injured thumb during most of the first month of the season.
Upton entered play Monday night with a .225 batting average and Gibson was asked before the game if he was close to giving Upton a mental day off again.
"I asked him today," Gibson said. "He wants to play. He's very determined. He just hasn't been able to find his swing path. On and off, but not consistently. He's worked so hard he's probably got a little too much on his mind right now."
Having too much on his mind could be one of the factors in his struggles.
"It's probably not as natural for him right now because he's trying to make certain adjustments," Gibson said of Upton's swing. "You're pulling off the ball, so maybe you close up, and the reality of it is it makes you pull off even more. It's just a vicious cycle sometimes."