PITTSBURGH -- The Cubs ended a 10-game losing streak last weekend when they won the first two of a three-game series against the red-hot Braves. But they were handed another series loss by the Pirates with an 8-7 defeat in 10 innings on Thursday afternoon at PNC Park.

• Box score

The Cubs have lost 15 of their past 19 games, a stretch in which they’ve lost nine games by five runs or more. What did we learn from the Pirates series? Here are a couple of observations, as well as a medical update on a Cubs coach after a scare in Thursday’s game.

A historically young staff
The series in Pittsburgh was another turn through the youngest part of the Cubs’ rotation, which has needed rookies and budding arms to step up after injuries to Marcus Stroman, Drew Smyly and Wade Miley.

Caleb Kilian, Matt Swarmer, Keegan Thompson and Justin Steele, who had a combined 41 career starts entering the series, each took his turn, to mixed results. Thompson’s six-inning, one-run outing in Wednesday night's 14-5 win was the highlight. In total, the starters allowed 19 runs (16 earned) in 18 innings, a number somewhat inflated by Kilian, the club’s No. 5 prospect, who allowed seven runs (five earned) in 2 1/3 innings on Monday.

Cubs historian Ed Hartig unearthed that the last time the sum of starts for Chicago’s pitchers going into a four-game series was 41 or fewer was from April 27-30, 1903, in Cincinnati. Alex Hardy (who made two starts), Carl Lundgren and Jake Weimer had a combined 29 starts entering that series.

It has been a different process recently than in months and seasons past for the Cubs’ pitching group, led by pitching coach Tommy Hottovy. Chicago has long had veteran influences making starts. But it’s going through a period of inexperience in MLB starting reps -- with some growing pains, but also some valuable looks at potential future pieces. Even the coaching staff has had to adapt.

“What Kyle Hendricks and Stroman and Miley need is completely different than what Steele and Keegan and Swarmer and Kilian, all these guys, will need,” Hottovy said. “So we take a lot of pride [in that work].”

Erase the errors
It helps young pitchers to have clean defense on balls in play. The Cubs have had trouble providing that consistently.

The Cubs committed 10 errors in the four-game series, moving their total to 43 on the season, which ranks the bottom half of the Majors. A few have come back to bite them, including four unearned runs charged to Daniel Norris on Wednesday, though in a blowout.

“We didn’t make the plays behind him yesterday, so I don’t want to put that on him,” manager David Ross said of Norris, who went on the 15-day injured list on Thursday with a left index finger strain. “It should have been a lot easier of an outing than we made it for him.”

Four errors occurred in Thursday’s finale, including consecutive fielding errors by Jonathan Villar and Patrick Wisdom -- each his eighth of the season -- to allow what turned out to be a crucial two-out run in the fifth inning.

“We’ve got to play some better defense and lock things down,” Ross said.

Bigger than the game
In the bottom of the first inning, the game was halted for six minutes as trainers rushed out to the Cubs’ bullpen, causing confusion among fans and in the dugouts. After the game, it was revealed that Chicago bullpen coach Chris Young was light-headed and needed to be evaluated.

“You don’t know if it’s a player or a coach. It kind of stopped everything,” Ross said. “You see the worry on people’s faces, and [we were] trying to gather some information, as well as there’s a lot going on down there.”

Young was taken to a hospital and checked out, and Ross said “everything is going to be fine.” He commended everyone involved, including members of the Pirates, on helping ensure Young was safe and healthy.

“The medical staff was on top of it,” Ross said. “I appreciate the umpires’ patience. The Pirates were extremely patient and sent their medical staff out there. We got him to the hospital, got him checked out, and he’s going to be all right.”