Nathan Eovaldi does not appear like he’ll be returning to the mound anytime soon.The 29-year-old Red Sox starter will undergo surgery Tuesday to remove “loose bodies” in his right elbow, according to a report from The Athletic, which cites an unidentified league source. Eovaldi had a similar procedure while with the Rays in 2018. #RedSox right-hander Nathan Eovaldi will undergo surgery tomorrow to remove the loose bodies in his elbow, a source tells The Athletic. Had similar procedure in 2018 and missed two months while with #Rays .— Ken Rosenthal (@Ken_Rosenthal) April 22, 2019WEEI later reported Eovaldi is expected to miss at least four to six weeks.MORE: Watch ‘ChangeUp,’ a new MLB live whiparound show on DAZNPer source: Eovaldi out 4-6 weeks with loose body removal in elbow. Similar to last season— Rob Bradford (@bradfo) April 22, 2019Eovaldi, who was originally placed on the injured list Saturday, is 0-0 with a 6.00 ERA in four appearances in 2019. He had his best start of the season last week when he allowed just one unearned run and three hits in six innings of work against the Yankees.“It’s just frustrating when you’re coming off a good outing and you’re taking the right steps forward, and you have to have this and you just can’t throw,” Eovaldi said last week, via ESPN. “For me to not be able to get full extension, I can’t throw like that.”The right-hander has pitched for five teams over his nine-year career. He joined the Red Sox last July in a trade with the Rays and helped them to their fourth World Series championship since 2004.Eovaldi was 2-1 with a 1.61 ERA in the postseason, his only loss coming in the Red Sox’s 18-inning loss to the Dodgers in Game 3. During the offseason, Eovaldi re-signed with the Red Sox for four years and a reported $67.5 million.The Red Sox began 2019 with a 2-8 record but improved to 9-13 after a sweep of the Rays over the weekend. They’ll begin a four-game series against the Tigers with a doubleheader Tuesday after the teams’ Monday matchup was postponed.