Tyler O’Neill, who had already missed the Boston Red Sox’s last four games, was left out of the lineup against the Kansas City Royals and placed on the injured list due to illness.

Boston Red Sox outfielder Tyler O’Neill has been placed on the 10-day injured list due to a lower left calf infection, retroactive to Aug. 4, the team announced Wednesday evening.

O’Neill had already been left out of Boston’s starting lineup for their series finale against the Kansas City Royals, which was going to mark his fifth consecutive absence. He has not taken the field since Aug. 2 against the Texas Rangers.

The soonest O’Neill can return is Aug. 14, also against the Rangers.

O’Neill was initially sidelined due to a stomach virus, and manager Alex Cora expected him to be back in the lineup by now. As a result of the leg infection, though, his return date has been pushed a week.

Infielder Enmanuel Valdez, who was already traveling with the Red Sox as a member of their emergency taxi squad, has officially been recalled from Triple-A Worcester to take O’Neill’s spot on the active 26-man roster. Boston also optioned reliever Cam Booser and activated reliever Chris Martin from the injured list.

This marks O’Neill’s third stint on the injured list this season. He was previously shelved with a concussion and right knee inflammation.

Despite playing in just 80 of the Red Sox’s 112 games so far in 2024, O’Neill still ranks second on the team in home runs and fifth in WAR. The 29-year-old slugger is batting .268 with 22 home runs, 45 RBI, a .900 OPS and a 2.3 WAR since the St. Louis Cardinals traded him to Boston in December.