Upton suffered a bruised right thumb after hitting the Miller Park leftfield line wall in Milwaukee after making a catch on a ball hit by Brewers second baseman Scooter Gennett in the seventh inning of San Diego’s 12-5 victory, its 13th win in the past 18 games.
He was replaced by pinch-hitter Clint Barmes in the eighth inning after going 1 for 4 with a double.
"It's a little sore," Upton said to MLB.com. "It snuck up on me. Most of the time you have time to break it down ... but I didn't. There isn't a better spot for padding [than] there. That railing is pretty inconvenient.”
"Unless I’m concussed and I don’t know it," he added. "Everyone keeps asking me about my face. If anything, it might’ve hit my glove, which is pretty soft."
Padres interim manager Pat Murphy says the team will keep an eye on Upton’s injury and added that if Upton is out for more than a day, they will be concerned.
Upton, who was the subject of trade rumors, is hitting .247 with a team-leading 18 home runs and 57 RBI this season in his first season in San Diego after being traded from the Atlanta Braves last off-season.
The Padres (52-54) are 8 1/2 games back of the Los Angeles Dodgers in the National League West and six games out of the second Wild Card spot in the NL.
- Scooby Axson