Phillies righty Howard placed on 10-day IL

On Saturday night, top Phillies pitching prospect Spencer Howard left his start due to a shoulder issue. A day later, he went on the shelf.

With two weeks left in the regular season, MLB Pipeline's No. 32 overall prospect was placed on the 10-day Injured List on Sunday with right shoulder stiffness.

Howard was in the middle of his sixth outing in the Majors when he departed his Saturday start at Miami after 3 2/3 innings. The Phils’ No. 2 prospect retired 10 of the first 11 batters to cruise into the fourth inning before running into trouble. With two outs, Jesus Aguilar singled and Matt Joyce walked. Brian Anderson followed with a homer to cut the Marlins' deficit to 5-3.

"It was taking him a few pitches to get loose every inning, so we took him out to be cautious," Phillies manager Joe Girardi told reporters. "He tested out well with our trainers, but obviously, we did not do any diagnostic testing. ... I would imagine at some point we will see how he feels tomorrow and evaluate him tomorrow. And if we have to do testing, we will."

Howard elaborated.

"Past couple of days, [it would] just feel a little tight in my shoulder and tonight was just slow to get warmed up,” the right-hander said. “And toward the end of the inning, it would feel good. The warmup process was just getting longer and longer.”

Last season, his second full professional campaign, Howard missed two months with soreness in the same shoulder.

"I'd say it's not as severe as that, but I got a comparable sensation,” he said Saturday. “Last year, it was pretty sharp and aggressive when I did throw, this ... just felt like a little rusty, a little slow to warm up, so I'm not necessarily concerned about it.”

In six Major League outings since debuting on Aug. 9, Howard went 1-2 with a 5.92 ERA and 23 strikeouts against 10 walks over 24 1/3 innings. His best start -- and first big league win -- came on Aug. 31 against the Nationals when the 24-year-old allowed two runs on five hits over five innings, striking out four and walking a pair.

The Phillies selected Howard in the second round of the 2017 Draft. Over three seasons in the Minor Leagues, the Cal Poly product assembled a 13-10 record and 3.28 ERA in 47 starts, striking out 281 and walking 74 over 211 1/3 innings.

In other news:

Ahead of Sunday's doubleheader, the Marlins called up their No. 7 prospect, left-hander Braxton Garrett. The 2016 first-round selection got the win in the nightcap in his Major League debut, allowing a run on three hits and two walks with six strikeouts over five innings, as Miami completed the sweep. Garrett made only four appearances in his first pro season in 2017 before undergoing Tommy John surgery and missing all of the following year. Last season, Garrett made 21 starts between Class A Advanced Jupiter and Double-A Jacksonville, compiling a 3.54 ERA.

Right-hander Jonathan Stiever, the No. 6 White Sox prospect, had his contract purchased and was promoted from the club's alternate training site in suburban Schaumburg and made his big league debut against Detroit. Getting the start, Stiever limited the Tigers to one run on two hits and two walks while fanning three over 3 2/3 innings. The 2018 fifth-round pick made 39 Minor League starts, including 26 last season, when he was 10-10 with a 3.48 ERA, 1.18 WHIP and 154 strikeouts over 145 innings for Class A Kannapolis and Class A Advanced Winston-Salem.

Tenth-ranked Red Sox prospect Tanner Houck is poised for his Major League debut on Tuesday night in Miami. The 24-year-old right-hander was with the 24th overall pick in the 2017 Draft and has made 66 appearances, including 50 starts, across three Minor League seasons. Last year with Double-A Portland and Triple-A Pawtucket, he was 8-6 with a 4.01 ERA, 1.40 WHIP and 107 strikeouts over 107 2/3 innings.