CHICAGO -- All-Star shortstop Dansby Swanson was activated by the Cubs on Saturday after he had been sidelined by a bruised left heel.

Swanson was in the starting lineup against the St. Louis Cardinals, batting sixth in his first big league game since he was injured July 5. He is batting .258 with 10 home runs and 36 RBIs in 83 games.

The 29-year-old Swanson, who signed a seven-year, $177 million contract with Chicago in December, played in 160 games in 2021 and 162 games last year in his final season with the Atlanta Braves. He said he was going "a little stir crazy" while he was on the 10-day injured list.

"I felt like I was everybody's honorable assistant," Swanson said. "I felt like hitting coaches, pitching coaches, like everybody, I felt like I was essentially an assistant coach for the last two weeks, which, it was driving me nuts. I love playing. I love going out there every day."

Infielder Jared Young was optioned to Triple-A Iowa to make room for Swanson on the roster. Young, 28, is batting .171 with a home run and five RBIs in 13 games with the Cubs this year.

Swanson tested his heel by running the bases. He also has been working in the batting cages to help maintain his timing with his swing.

"I wouldn't be out there if I didn't feel like I was able to be a productive baseball player," Swanson said. "Finally got to that point, and we're ready to go."

Swanson made his big league debut with Atlanta in 2016 and helped the Braves win the 2021 World Series. He hit .277 with 25 home runs and a career-best 96 RBIs in his final season with Atlanta.

"Dansby's really important to our success," Cubs manager David Ross said, "and his play [has] been missed. ... It's nice to have him back. He's worked really hard, been itching to get back."