The Chicago Tribune’s Marlen Garcia on a sudden shift in the Eastern Conference’s balance of power.

Free agent Ben Wallace has accepted the Bulls’ contract offer, a source close to the situation confirmed Monday night.

The 6-foot-9-inch center reportedly had an offer from the Pistons that would have paid him an estimated $48 million over four years. A source close to the Bulls confirmed they also had made a four-year offer.

ESPN’s Chad Ford on what-happens-next :

The signing clearly upgrades the Bulls’ front court, albeit at an exorbitant price. The Bulls will have to use roughly $13.5 million of their projected $16.7 million in cap space to secure Wallace.

However, Wallace adds the veteran toughness and defensive presence the Bulls felt they lacked up front.

Look for the Bulls to now explore trade scenarios involving Tyson Chandler.

One potential opportunity, according to sources, is New Orleans, which is mulling a Chandler-for-P. J. Brown swap. Brown is in the last year of his contract, which would give the Bulls even more cap relief next season.

The Bulls also have explored Chandler trade scenarios with the Hawks (via an Al Harrington sign-and-trade) and the Warriors.

The move puts the Pistons in a difficult position.

They lose Wallace for nothing and don’t have anything more than the $5.1 million mid-level exception to offer to potential replacements.

There are a few starting center-caliber free agents out there, such as Joel Przybilla and Nazr Mohammed, but none who can give the Pistons what Wallace did.