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]

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Example Sentences

A major concern has been that the company has fallen behind on its artificial intelligence updates, which has kept some investors on the sidelines.

From Barron's • May 6, 2026

This term, he has spent a long period on the sidelines injured.

From BBC • Apr. 30, 2026

Many other central banks in Asia too have decided to stay on the sidelines until the impact of the war becomes clearer, though Australia, Singapore and the Philippines have all opted for tightening.

From The Wall Street Journal • Apr. 28, 2026

On top of that, market volatility pushed many to sell on days that the market rallied, and sit on the sidelines instead of buying dips.

From MarketWatch • Apr. 27, 2026

The girls in my cabin played kickball and learned dance routines, but I always sat on the sidelines.

From "A Place at the Table" by Saadia Faruqi and Laura Shovan