Five considerations now that Peyton Manning has told the San Francisco 49ers and Tennessee Titans he plans to sign with the Denver Broncos:

Big sighs of relief: Arizona, Seattle and St. Louis no longer must worry about defending against a Manning-led 49ers offense. A healthy Manning would have made the 49ers even more formidable than they were while going 5-1 against the division last season. It's looking like the Seahawks will be the team in the division with the best shot at upgrading their quarterback situation.

Harbaugh must take lead: The seemingly special bond between 49ers coach Jim Harbaugh and 2011 starter Alex Smith could need some repairing. That should not be too difficult if Harbaugh has been forthright with Smith throughout the process. The 49ers, like the Cardinals, will want to define their interest in Manning as a special case unrelated to their incumbent quarterback. Re-signing Smith should be a no-brainer now.

Smith's only logical option. Smith has made it known he wants to continue playing for the 49ers. Hurt feelings suffered during negotiations and the Manning diversion should not be grounds for divorce. Unless Smith acts hastily out of anger, which seems unlikely given his temperament, the 49ers should now be able to re-sign Smith to a deal that gives them the flexibility to hand things over to Colin Kaepernick in the next couple years if Smith falters. The 49ers did lose some leverage, however, when Manning picked Denver over Tennessee. A deal with the Titans would have pushed Matt Hasselbeck onto the market.