CHICAGO -- Chris Sale will make at least one more minor league rehab start before the Boston Red Sox decide if their ace is ready to join their rotation after being sidelined all season because of a rib injury.

Manager Alex Cora said Friday the seven-time All-Star is close to returning.

Sale struck out seven over four innings for Double-A Portland on Thursday. Cora said his mechanics were sound in his third rehab outing and he felt "physically great." The 33-year-old left-hander is scheduled to pitch for Triple-Worcester on Wednesday.

"We'll see," Cora said. "He's getting close. We'll talk about it and go from there."

Sale, signed through 2024 on a five-year, $145 million deal, fractured his rib cage in spring training. He is 114-74 with a 3.03 ERA and 2,059 strikeouts over 321 big league appearances. He has thrown 42 2/3 innings for the Red Sox since the end of the 2019 season.

Sale went 5-1 with a 3.16 ERA in nine starts in his return from Tommy John surgery last year. He missed the 2020 season.

The Red Sox were tied for second in the AL East with the Toronto Blue Jays at 43-33 entering Friday's game against the Chicago Cubs. They went 20-6 for their highest June win total since a 20-9 showing in 1990.

Boston closed the month by dropping two of three at Toronto. Outfielder Jarren Duran and closer Tanner Houck did not accompany the team because they weren't vaccinated for COVID-19.

Duran said being away from his teammates convinced him to reconsider his stance. He vowed to be available when Boston returns to Toronto in late September. Houck wouldn't say if he will be, too.

"I just miss the boys and miss playing baseball," Duran said. "It's kind of the deciding factor."