"Rhett Bomar is out. Sage Rosenfels is in.

And right now he's the only other quarterback besides Eli Manning on the roster, so the 32-year-old Rosenfels better pick up the Giants' offense fast.

"I'm going to be spending a lot of time in that hotel room studying my tail off," Rosenfels said Saturday in a statement released by the Giants.

The Giants obviously believe he can, since they cut Bomar and carried only two quarterbacks after trimming their roster to 53 players Saturday. The Giants may still add Bomar to the practice squad if he clears waivers Sunday, but Rosenfels figures to be the only active backup quarterback when the season opens on Sunday.

That means if something happens to Manning, Rosenfels - whose trade from the Vikings to the Giants became official when he passed his physical Saturday - will have to run an offense he had never seen before Saturday.

"It is a foreign language," Tom Coughlin said. "However, he had a numbering system before similar to ours. He will also have a package of plays he'll be able to perform with. You can't go back to Day 1. But you have to build them a basic understanding and foundation, which is the way in which they communicate."

Along with Rosenfels, the Giants also acquired RB/KR Darius Reynaud from Minnesota for a fifth-round pick in 2011 and a conditional draft pick in 2012. Coughlin praised his versatility, saying he could see playing time as a punt returner, kickoff returner, gunner, running back and receiver."