Jameson Taillon’s return from the injured list lasted just two outings.

The right-hander is heading back on the 15-day injured list with a left groin strain, Cubs manager Craig Counsell told reporters in San Francisco on Wednesday. The Cubs are recalling right-hander Javier Assad from Triple-A Iowa, and he will start on Saturday in Colorado against the Rockies.

Taillon missed a month-and-a-half with a calf strain earlier this summer.

“We’re going to put him on the injured list,” Counsell told reporters at Oracle Park in San Francisco before Wednesday’s game against the Giants. “He threw about 12 or 14 pitches, and it went pretty well, but I think we’re in a position where we’re going to be safe here.

“If we can skip a start, we’ll probably be in good shape and expect this to be the minimum [stint on the IL]. He’s got a little something going on and we don’t want to risk it.”

That means Taillon could be back in the Cubs’ pitching fold in early September. Taillon tossed five innings of one-run ball in Sunday’s 4-3 win over the Los Angeles Angels but left after throwing just 62 pitches in the outing.

“He had a little groin tightness — left groin tightness — so it was kind of precautionary,” Counsell told reporters at Angel Stadium after the start. “That was why I took him out.”

It’s the latest knock for a rotation that has been beleaguered by injuries this season. They started as the Cubs began spring training, as Assad suffered an oblique injury that caused him to miss the ramp to the season, the first month of the year and then a reaggravation of the injury in a rehab outing in April caused him to be out until August 12.

In April, Justin Steele went down and underwent season-ending elbow surgery. Shota Imanaga missed over a month with a hamstring injury and Taillon missed six weeks with a calf strain before returning earlier this month.

Even the Cubs big reinforcement at the trade deadline – Mike Soroka – suffered an injury two innings into his debut with the Cubs.

Despite those hiccups, the Cubs rotation has thrived since July 1. Cubs starters have a 2.91 ERA in that span, the best mark in baseball.

“We’ve pitched well,” Counsell told reporters in San Francisco. “We’ve pitched very well out of the starting rotation, no question about it. Everybody’s responsible for that. Each five guys are taking pretty equal turn in that, and it’s made a consistent baseball team.

“How are starters have pitched have been a big reason in our consistency and we’re going to need it for the last 30 games.”

Taillon had been solid this season, when healthy. He allowed just two runs on eight hits in 11 innings in his two outings back from his calf strain. Taillon has thrown 11 quality starts in his 19 outings this season and has allowed three or fewer runs in 15 of those games. Four clunkers in which he’s allowed five or more earned runs have spiked his ERA to 4.15 across 106.1 innings this season.

Assad has a 3.86 ERA in three starts this year. He tossed six innings of one-run ball with four strikeouts in last Friday’s 3-2 win over the Angels. He’ll presumably continue to fill Taillon’s role in the rotation until he returns.