Arrieta will have surgery to remove bone chips in his pitching elbow. The 33-year-old right-hander was 8-8 with a 4.64 ERA in 24 starts, and had been trying to pitch through the injury for the last month.
Robertson, a right-handed reliever, had Tommy John surgery Thursday and probably will miss all of the 2020 season as well. Signed to a two-year, $23 million contract in the offseason, he was able to pitch just 6⅔ innings this year.
Robertson tweeted that he hoped to be able to pitch next season, though pitchers usually miss a full year from the time of the surgery.
A heartbreaking end to my season, but I'm going to work hard to get back and contribute big next year. Thanks for all the support and prayers.— David Robertson (@DRob30) August 17, 2019
Quinn strained his right groin trying to beat out a grounder in the eighth inning of the Phillies' 8-4 victory over the San Diego Padres on Friday night. He is batting .213 with three doubles, four homers and 11 RBIs in 44 games.
Philadelphia activated right-handed reliever Jared Hughes after claiming him off waivers from Cincinnati earlier this week. Hughes went 3-4 with a 4.10 ERA in 47 games with the Reds this season.
Arrieta was put on the injured list Wednesday, three days after struggling through what would be his final start of the season. Arrieta, who had an MRI on Thursday before the final decision to have surgery was made, said Wednesday that he accepted he could no longer pitch effectively because of the bone spur.
"I wanted to try and make it work for as long as possible," Arrieta said. "I realized that I'm not able to give the team what it needs. The pain is something I can deal with, but it's the loss of feel and the ineffectiveness as the outings wear on. I think that the time is right to make it happen now and get a guy in the rotation that has pitched really well for us and give him an opportunity to get back to the form where he was at earlier in the season for us. I think we'll be in good hands."
Zach Eflin, who was relegated to the bullpen last month after struggling as a starter, returned to the starting rotation in Arrieta's absence.
Information from The Associated Press was used in this report.