on the sidelines

Idioms  

1. Observing rather than taking part, out of the action, as in Bolivia's neighbors remained on the sidelines, waiting to see which faction in the dispute would prevail. This idiom comes from sports. The sidelines are the two lines defining the sides of the court or playing field and the area immediately beyond them where, in such sports as football, the non-playing team members sit. [First half of 1900s]

---

Example Sentences

With Alisson still out with a hamstring injury and Mamardashvili facing a spell on the sidelines, Woodman looks set to play against his boyhood club Crystal Palace at Anfield this weekend.

From BBC • Apr. 21, 2026

He also wants his firm to have capital on the sidelines in case of an economic slowdown.

From The Wall Street Journal • Apr. 19, 2026

After that debacle, Mom and Pop would remain on the sidelines until after World War II, when the American economy boomed once more.

From Barron's • Apr. 15, 2026

Last April, retail investors in the U.S. stepped in to aggressively buy the post-“liberation day” dip in stocks while Wall Street professionals generally remained on the sidelines.

From MarketWatch • Apr. 6, 2026

The group looked at me, seemingly all at once, since I was now the only person on the sidelines.

From "The Other Wes Moore: One Name, Two Fates" by Wes Moore