The team placed fan-favorite wide receiver Victor Cruz on injured reserve with a hamstring injury.
Tynes sprained his left, non-kicking ankle on Friday during practice and the kicker didn't improve much overnight. It appears he will not be able to play Sunday against the Detroit Lions. Tynes, who is 5-for-8 on field goal attempts this season, tested his ankle in the morning walkthrough on Saturday, and the Giants then decided to sign Graham to cover themselves.
Graham, 32, spent the past seven seasons with the Cincinnati Bengals. The 10-year veteran has converted 196-of-230 (85.2 percent) of his field-goal attempts.
Cruz suffered a hamstring injury Monday and the injury did not appear to be one that would keep the rookie out indefinitely. The 6-foot-1 wide receiver became an instant fan favorite during the preseason, when he had six catches for 145 yards and three touchdowns in his preseason debut against the Jets.
He finished the preseason with 15 catches for 297 yards and four touchdowns. However, he played in just three regular-season games and had no catches.
Last week, he was a healthy inactive while wide receiver Ramses Barden suited up.