Latos, who is tied for third in the National League with 10 victories, will be placed on the 15-day disabled list on Friday with a strain to his left side.
Latos said he suffered the injury attempting to hold back a sneeze on Friday in Colorado, a day after he improved to 10-4 and lowered his ERA 2.45 with a victory in Washington.
"I held my sneeze walking down the [dugout] steps and felt a little pull," Latos said just before a workout at PETCO Park in advance of Friday's game against Arizona, the first game of the second half of the regular season.
Latos sheepishly told teammate and fellow pitcher Tim Stauffer about the pain and felt a little embarrassed. Latos said that this is the first time he felt pain in his side.
The decision to place Latos on the disabled list coincides with a planned break for the 22-year-old, as the Padres are closely watching his innings and workload.
The team will place Latos on the disabled list retroactive to July 9, the day after his start against Washington. He would then be eligible to return on July 24, in time for a start in Pittsburgh, if there are no complications with the strain.
Considering the All-Star break gave the Padres a chance to reset their rotation, Latos likely wouldn't have pitched until July 24 anyway, especially with a day off on Monday, as the team could have skipped him in the rotation had he been healthy.
"We'll go through and make sure we're not risking anything," said Latos, who will travel with the team on Monday as they start a six-game road trip to Atlanta and Pittsburgh on Tuesday.
"To be honest, if it had to happen, it's a good time for it to happen."
Latos said that he was feeling "fine, I feel great," before the Padres workout on Thursday, though he understood the cautious approach the team was taking.
San Diego manager Bud Black said that he's still holding to his preseason figure of between 150-180 innings for Latos this season. He has already thrown 106 2/3 innings so far.
The Padres will add relief pitcher Ernesto Frieri to the 25-man roster before they play the Diamondbacks on Friday. Frieri, who worked out with the team on Thursday, was picked to play in the Triple-A All-Star Game, but had to pass when he learned of his promotion.
Frieri was 3-1 with a 1.43 ERA and 17 saves in 34 games with the Beavers. Opponents were hitting .114 against him.
Also Thursday, outfielder Kyle Blanks, who has been on the disabled list since May 20 (retroactive to May 18) with a strained right elbow, had a second MRI where he received some good news. Blanks was told the elbow looks better and that surgery seems a remote possibility.
"It seems like [surgery] is a very slight possibility now," said Blanks, who also received a cortisone shot on Thursday. "It's not likely going to happen."
Blanks, who was hitting .157 with three home runs and 15 RBIs with the Padres, last appeared in a game on June 14 with Triple-A Portland. Now he's hopeful he can return this season.
"Being 100 percent, that's the objective," Blanks said. "I'm optimistic. I would like to play again this year."
Corey Brock is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.