Jenkins didn't report to the team's practice October 30 and was suspended indefinitely the next day.
Manning has started 207 consecutive regular-season games for the Giants and is one start shy of tying his brother Peyton for second on the all-time list.
"He's our quarterback", McAdoo told reporters Monday, via Newsday.
Conte victory? Chelsea technical director Emenalo resigns
It is understood that Emenalo had become frustrated at being caught in the middle of a power struggle between Conte and the board. Emenalo: "This has been a very hard decision to make, but one I believe is right for both myself and my family, and the club".
After making the Pro Bowl past year, his first with the Giants, Jenkins has returned an interception for a touchdown against the Broncos, defensed six passes and made 24 tackles this season.
The Giants defense allowed 51 points on Sunday against the Rams with Jenkins out.
In an attempt to salvage their disastrous season, the Giants also reacquired linebacker Deontae Skinner after he was re-signed and waived by NY earlier this year.
Jenkins, 29, recorded an interception for a touchdown against the Denver Broncos on October 15 and has 24 tackles in six games this season.
The struggling Giants (1-7) play the winless San Francisco 49ers this week.