Sunday night's Super Bowl loss was a disappointing one for Tom Brady, but should it be his last NFL game ever?

The New England Patriots quarterback had lost, once again, to the New York Giants in the biggest game of the year 21-17. His head down, staring at the floor, Brady didn't move for nearly 15 minutes in the locker room at Lucas Oil Stadium after the loss. Photographs caught the quarterback's sad eyes as his wife, supermodel Gisele Bundchen, tried to comfort him with a hug.

They say you should leave on a high note, but this might be the two-time MVP's best chance to pick up the pieces and start a new chapter in his career. Below is a list of five reasons why Brady should call it quits.

He's getting old. At 34 years old, Brady has been playing for the Patriots since 2000. Most football players retire between their mid to late 30s (with the exception of kickers and punters) simply for physical reasons, and he's nearly a decade older than most of his teammates. Knees go out, players get hurt, and their abilities diminish. Yes, Brady has as sharp a mind as any in the NFL, but his legs can't save him from big hits anymore.

His team is changing. Once the haze of the hangover goes away, people start to remember that the end of the Super Bowl means the end of contracts. Although players won't talk about their free-agent status for a while, it can be guaranteed a few of them won't be playing for their team again.

According to Bleacher Report, leading rusher BenJarvus Green-Ellis is finishing a one-year $1.8 million deal and may receive an offer he can't refuse from another team. Wes Walker, the usually reliable wide-receiver who dropped a pass in the fourth quarter, will also be a free agent. Brian Hoyer, Thomas Clayton, Deion Branch, Matt Slater are also free agents. Brady faces next season's training camp with the prospect of many new faces in huddle. Aging quarterbacks don't have the luxury of waiting for new teammates to develop.

 Gisele wants to have a big family. Brady and his Brazilian supermodel wife have one child, Benjamin Rein, born in December 2009, and the cover girl claims she loves Brady's son from a former relationship as her own. In an April 2010 interview with British tabloid Hello!, Gisele said she can't wait to give Benjamin more brothers and sisters . I want to have lots of children, she said. It doesn't matter if my body changes. It is the most marvelous thing.  Of course, the couple is wealthy enough to hire more than a few nannies, but Gisele's biological clock is one good reason for Brady to retire and spend quality time with his sons and babies-to-be.

A whole new phase of his career awaits. A boatload of money awaits the handsome quarterback as a commentator and analyst. Known for his pithy quotes and deep knowledge of the game, Brady could take early retirement as a chance to spend Sundays in the broadcast booth, and not worrying about the Giants' Justin Tuck hitting him all the time.

His legacy is already set. If Brady were to retire now, he already has enough credentials to get into the Hall of Fame. He has three Super Bowl rings, is a two-time Super Bowl MVP, and has broken the record for most touchdown passes in the NFL. If he retired now, his career accomplishments would overshadow the loss from the last game he played. His odds of adding to such a legacy grow slimmer every year he's closer to 40 years old. Taking the supermodel wife and a TV job doesn't sound too bad by comparison.