Red Sox activate IKF, call up Jedixson Paez to start vs Mariners as rosters expand

Boston Red Sox used the first day of September roster expansion to add depth and fill a rotation hole. They selected right-hander Jedixson Paez from Triple-A Worcester to start Tuesday night against the Seattle Mariners at Fenway Park, reinstated infielder Isiah Kiner-Falefa from the 60-day injured list, and shuffled the 40-man roster around those two moves.

Boston entered the night 75-63 and third in the American League East. First pitch against Seattle was set for 6:45 p.m. ET, with Bryan Woo lined up for the Mariners.

Jedixson Paez gets first Red Sox start after Rule 5 detour

Jedixson Paez, 22, will make his first start in a Boston uniform and his first start in the majors. The Venezuela native signed with the Red Sox as an international free agent in January 2021. Chicago took him in the 2025 Rule 5 Draft, and he made his big-league debut with the White Sox this spring. Those three relief outings did not go well: six runs in 3.0 innings. Chicago designated him on April 1, and he was returned to Boston three days later.

He spent most of 2026 at Double-A Portland before a mid-August bump to Worcester. Combined between those two clubs, he is 4.11 ERA over 61.1 innings, with 74 strikeouts. His walk rate has been tiny. In three Triple-A starts, he allowed four earned runs in 12.1 innings and struck out 18. His last outing, Aug. 25 against the Yankees’ Triple-A affiliate, was five innings, one run, and eight punchouts.

The call-up is a spot start. Sonny Gray is getting extra rest, and Boston needed an arm who was already lined up. Paez had been stretched toward five innings in August after earlier workload limits.

Kiner-Falefa returns after two-month forearm layoff

Kiner-Falefa’s activation was the expected September move. The 31-year-old utility infielder has been out since mid-June with left forearm inflammation, later described as a stress reaction. He played nine rehab games at Worcester, hitting .241 (7-for-29) with a double, three RBI, six walks and three stolen bases. He started at second, short, third, and DH during that stint.

Before the injury, he had played 47 games for Boston and hit .277 (33-for-119) with 19 runs and 13 RBI. He started 21 games at second, nine at short and five at third. The Hawaii native, originally a 2013 fourth-round pick of the Rangers, gives manager Alex Cora another glove up the middle while Trevor Story and others handle everyday work. He can also cover first while Willson Contreras remains on the injured list.

Career-wise, Kiner-Falefa has hit .263 with 38 home runs in 967 major-league games across Texas, the Yankees, Toronto, Pittsburgh and now Boston.

Rivera’s season ends; Harris designated

To open 40-man space, Boston recalled Eduardo Rivera from Worcester and immediately placed the 23-year-old left-hander on the 60-day IL with a lumbar strain. That move effectively ends his 2026 season. Rivera made four appearances (three starts) for the Red Sox this year, allowing seven earned runs in 10.0 innings. He was 7-2 with a 2.59 ERA and 71 strikeouts in 26 minor-league games this season.

Brett Harris, acquired from the Athletics on July 1, was designated for assignment. The 28-year-old appeared in one game for Boston, a July 9 start at first base against Chicago. He has a .192 average in 74 career major-league games.