CLEVELAND -- Hours after Angels starter Felix Pena was carried off the field Saturday night with a right knee injury, manager Brad Ausmus said he wasn’t overly optimistic about the outlook. His words, unfortunately, would later prove prophetic.

Pena was diagnosed with a torn ACL, kicking off a slew of roster activity prior to the Halos’ series finale against the Indians in Cleveland.

Shortstop Andrelton Simmons (left ankle bone bruise and sprain) and right-handed pitcher Griffin Canning (right elbow inflammation) also joined Pena on the injured list. Taking their place was infielder Wilfredo Tovar, first baseman and left-handed pitcher Jared Walsh and righty reliever Luke Bard.

“You’ve got to keep plugging away,” Ausmus said of the injuries. “You can’t get caught up in what could have been or what should have been. It’s what it is. It’s not how we would have scripted this season for sure. But we have to find a way to win games, regardless.”

Pena suffered the ACL tear while covering first base on a grounder to Albert Pujols in Saturday’s 7-2 loss to Cleveland. The 29-year-old, who posted a 4.58 ERA in 96 1/3 innings this year for Los Angeles, was originally diagnosed with a right knee sprain. However, the additional tests revealed a grimmer situation.

“We won’t know really the extent of the injury until the swelling goes down, which takes 10 to 14 days,” Ausmus said. “They can’t do surgery until the swelling goes down. The recovery will be determined by what they find.”

With Pena now out of action, the Angels plan to promote left-handed pitcher Patrick Sandoval to start Monday night in Cincinnati.

“It’s very exciting,” Sandoval said with a giant smile as he unpacked in the Angels’ clubhouse. “It’s a dream come true.”

Sandoval is the Halos’ 11th ranked prospect, per MLB Pipeline. The 22-year-old southpaw was acquired by Los Angeles in the Martin Maldonado deal last season. He was originally drafted by the Astros in the 11th round of the 2015 MLB Draft.

This season, Sandoval posted a 3.60 ERA and struck out 32 in 20 innings at Double-A before earning a promotion to the Angels’ Triple-A affiliate. He has not had as much success in the PCL, owning a 6.41 ERA in 15 starts, striking out 66 and walking 35.

“I don’t get too caught up in [the PCL numbers],” Ausmus said. “I guess you could look at strikeouts and walks, the only thing you could really look at. He’s going to get an opportunity. He’s generally, over the past year, pitched really well.”

Regardless, Los Angeles needs the rotation help. Andrew Heaney’s impending return is on the horizon -- he’s set to throw a simulated game in Cincinnati on Monday -- but the lefty probably won’t be ready to return to the rotation until next weekend at the earliest.

As for Simmons, the injury, which occurred in the batting cages prior to Saturday’s game, is to the same ankle that he injured earlier this season. However, the shortstop indicated the sprain is to a different portion of his ankle.

“We’re not sure on the exact time frame for [Simmons],” Ausmus said. “It’s just going to depend on how quickly he seems to get past this. But it’s certainly going to be at least a couple of weeks.”

Canning, meanwhile, said that he had recently been dealing with some tightness, which he says began after his most recent outing, a scoreless six-inning performance against the Tigers on July 30. He underwent an MRI on Saturday, but the tests revealed nothing alarming.

“Anytime you have any injury, you kind of worry,” Canning said. “But I think I definitely could have still thrown tomorrow. Just sat down with the medical staff, Brad and [pitching coach Doug White], and just thought it was a better idea to for sure see what’s going on.”

The Angels’ replacements arrived prior to Sunday’s 6-2 loss in Cleveland.

Walsh owns a .572 OPS in 36 Major League plate appearances in 2019. He has also logged 4 1/3 innings of relief for Los Angeles this season, allowing just one run. Bard has posted a 5.68 ERA in 22 big league appearances this season, while Tovar hit .195 with three RBIs in 46 plate appearances for the Angels in June.

Bard appeared in Sunday’s game, but was struck on the back of the right arm by a liner off the bat of Indians first baseman Carlos Santana. The righty exited the game in the fifth and was later diagnosed with a right triceps contusion.

“I don’t know how much sleep they’ll have under their belt,” Ausmus joked. “For one day, you can deal with it.”