Be still/back in the game
Definition 1 of 2
Pro Tip 1/3Regained Momentum
Used when someone or something has recovered strength or popularity after a downfall. 
The politician was back in the game after the latest polls showed a surge in support.
Pro Tip 2/3Business Revival
Refers to a company or product making a comeback in the market. 
With its innovative approach, the aging brand proved it's still in the game.
Pro Tip 3/3Competitive Spirit
Highlights one's determination to remain relevant in a competitive situation. 
He trained relentlessly to be still in the game against younger athletes.