PHILADELPHIA -- Major League Baseball's new rule regarding home-plate collisions was at the center of a play in the bottom of the sixth inning on Sunday in a 4-3 victory over the Marlins at Citizens Bank Park. The Marlins threw out Tony Gwynn Jr. at the plate, but Philadelphia manager Ryne Sandberg asked for umpires to review the play, because he thought Miami catcher Jeff Mathis blocked the plate with his leg before he had the ball.

The umpires ruled that no violation was observed, but replay showed Mathis had his leg in front of the plate before he caught the ball from Marlins shortstop Adeiny Hechavarria.

"I think that nobody really knows what the rule is, honestly," Gwynn said. "Mathis is blocking the plate the entire time, even as he's waiting for the relay throw. As it was explained to me, because I hadn't started my slide yet before he got the ball, he's allowed to block the plate, but that's not how it was explained in Spring Training, so I think there's going to be a lot of that going on until there's a definitive interpretation of what that rule is."

The new rule, 7.13, section 2, reads as follows: "Unless the catcher is in possession of the ball, the catcher cannot block the pathway of the runner as he is attempting to score. If, in the judgment of the Umpire, the catcher without possession of the ball blocks the pathway of the runner, the Umpire shall call or signal the runner safe. Notwithstanding the above, it shall not be considered a violation of this Rule 7.13 if the catcher blocks the pathway of the runner in order to field a throw, and the Umpire determines that the catcher could not have fielded the ball without blocking the pathway of the runner and that contact with the runner was unavoidable (emphasis added)."

In the replay, Mathis' leg is in front of the plate as he fields the throw, which he receives before Gwynn arrives exactly at the spot where he is positioned. He then applies the tag, in line with the rule as it is written.

Naturally, the Marlins saw it that way.

"Hech made a great throw, and the ball got there before [Gwynn] got to me," Mathis said. "I think that's why they made the rule that they did. I think that's the explanation they were given."

"Once you catch the ball, you can block the plate," Marlins manager Mike Redmond said. "It looked to me like it was clean."

But Sandberg said Mathis did not give Gwynn a lane or view of home plate, which was his interpretation of the rule.

"I felt like Gwynn had to alter his slide a little bit, maybe his path a little bit just because the plate was blocked, so there was some confusion there," Sandberg said. "I went back out and asked about it and they said if contact with the [Mathis'], foot would have been made before he had the ball then that's blocking the plate. But then on the other side of the coin, they say that the catcher needs to give the baserunner a lane to home plate and give them a view of the plate."

Sandberg threw up his hands.

"I'll have to do some research on that," he said.

Said Gwynn: "As it was explained to us, is there ever a point you're allowed to have any foot, glove, leg in front of the plate before you have the ball? And to me, clearly that was the case, but apparently in New York [where they reviewed the play], it wasn't.

"That's where the tricky part comes in. You don't know exactly what the umpire's looking at. The last thing I want to do is run the guy over, I'm ejected and suspended, possibly fined. I can't say any of that is going through my head at the time. We're told to slide directly into home plate, so that's what I did, thinking we should get the call based on what was going on."