DALLAS -- The herniated disc forcing Orlando Magic center Dwight Howard to go under the knife might also keep him from winning an unprecedented fourth consecutive Defensive Player of the Year award.

PODCAST
Mavs coach Rick Carlisle dishes on the state of his team now that they've clinched a playoff spot. He also talks about Delonte West's "West willy" and why he's gone with Vince Carter over Shawn Marion in the last couple of games. Listen

Howard ranks third in blocks and first in rebounding, and without him the Magic are giving up significantly more points and a higher field-goal percentage. If Howard is indeed out of the running, will it force voters to seriously examine alternative candidates for an award that has primarily gone to a big man for the last 23 seasons?

"Shawn Marion for Defensive Player of the Year," Mavs coach Rick Carlisle campaigned once again Friday morning. "It'll be interesting. I still maintain that Marion's deserving based on how he's guarded so many different positions well and the fact that we're the top defensive team in the Western Conference. He's holding guys to under 35 percent shooting and low free throws and high turnovers. So, I think the case is there."

Howard wasn't the only big-man candidate worthy of consideration.

New York Knicks center Tyson Chandler -- sorry, Mavs fans -- is a leading candidate after he finished third in the voting last season with Dallas. He's averaging 10.0 rebounds, has 87 blocks. Just like he did with the Mavs, Chandler has helped the Knicks rank in the top 10 in scoring defense and field-goal percentage defense.

Oklahoma City Thunder power forward Serge Ibaka is another top candidate. The 6-foot-10, 235-pounder leads the NBA in blocked shots by an obscene margin. He has 221, 92 more than the Clippers' DeAndre Jordan. Ibaka is averaging 3.57 blocks a game and 6.36 blocks per 48 minutes.

Marion is the Mavs' defensive stopper, assigned to the opponents' top scorer. What separates Marion from most so-called stoppers is that he's called upon to guard players from power forward LaMarcus Aldridge to point guard Chris Paul.

In Wednesday's game against the Houston Rockets, Carlisle chose to start Marion defending Rockets point guard Goran Dragic even though Delonte West was on the floor.