Padres left-hander Drew Pomeranz, who was sidelined 10 days due to a strain in his pitching shoulder, was activated from the injured list on Saturday. But the optimism surrounding Pomeranz’s return was tempered a bit with this bit of news: fellow left-hander Adrian Morejon has landed on the IL in his place.

Morejon was slated to start the Padres' game against the Rockies on Saturday. Fellow rookie Michel Baez took his place. The nature of Morejon's ailment remains unclear, and Padres manager Jayce Tingler said he could not divulge the specifics.

"I can't get into a lot of details with it, but I can say that we're hopeful it'll be a really short stint and he'll be back with us shortly," Tingler said.

Major League Baseball has instituted a COVID-19 list this season, although clubs will not announce which players are placed on it due to privacy laws regarding individuals’ health. Players may address their status if they wish, though they are not required to do so.

It's important to note that merely being placed on an IL without further explanation is not confirmation that a player has tested positive for COVID-19. For example, potential exposure to a person who has the virus can be sufficient cause. So, too, are symptoms attributable to other illnesses, like a head cold.

Tingler was pressed on the nature of Morejon’s absence, but he wouldn't divulge details, only noting that he expected a speedy return for the 21-year-old left-hander. There is no minimum length of stay on the COVID IL.

"I'm sorry to be vague on it," Tingler said. "But we've got to respect everything going on. Like I said earlier, and I'll echo this again, we're hopeful he'll be back very soon, as in a couple days."

As for Pomeranz, his return is a huge boost for the Padres' bullpen, which got a separate jolt on Saturday afternoon with the acquisition of right-hander Trevor Rosenthal from the Royals.

Pomeranz threw a scoreless eighth inning in Saturday's 4-3 walk-off loss, extending his scoreless streak to 11 outings. He's given up just two hits all season.

"Nothing crazy, just needed a couple days," Pomeranz said of the injury. "Got a few days, and now we're back at it."

With Kirby Yates likely done for the season due to bone chips in his right elbow, Pomeranz had briefly assumed the closer role before his own injury. It's unclear whether he'll be thrust back into that position, given the addition of Rosenthal. But he doesn’t seem too concerned.

"Just tell me when you need me to pitch, and I'll be ready," said Pomeranz, who signed a four-year, $34 million contract with San Diego last Nov. 27.

The Padres’ bullpen started the year slowly, though it's been much sharper over the past week or two. Still, the team's 5.35 relief ERA ranked 24th in baseball entering Saturday.

With the return of Pomeranz and the addition of Rosenthal, this weekend could mark something of a turning point for the Padres' relief corps.

"As of lately, guys have been pitching really well," Pomeranz said. "But we'll take all the help we can get down there. Getting a guy like Trevor down there is a huge plus.

“Kirby going down -- that was obviously a big hit for us. But we know we're going to have to pitch well late in the game for us to be successful, and we're super excited to have him on board."