Peyton Manning and Tom Brady defined an era of professional football together. That era could be over. Mark J. Rebilas USA TODAY Sports

Hey football fans: Are you ready for Brady-Osweiler I in two weeks?

You might not have a choice. The NFL's storied quarterbacking clash between Peyton Manning and Tom Brady is in serious jeopardy now.

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Manning might still be sidelined with a torn foot ligament. Or, the Broncos might shut down a healthier Manning in hopes his arm regenerates for a run. Either scenario would prevent Brady-Manning XVII from happening in two weeks.

That's a shame; the two quarterbacks could've restored the luster lost when Manning and the Broncos lost two weeks ago.

Now, the matchup will probably feature only one undefeated team -- and only one all-time great quarterback.

(h/t Boston.com)