This is something I noticed a couple days ago during the game, and Paul Pierce pointed it out after practice today: The Celtics struggled with Jameer Nelson coming off the pick-and-roll. (WEEI)

The Celtics also want to figure out their pick and roll coverage. Jameer Nelson burned them in the second half when they went under the screen. He’s too good a shooter to allow him open looks.

“We’ve got to figure out a way to stop Jameer Nelson in the pick and roll,” Pierce said. “He really got hot in the second half. We’re far from being where we want to be.”

When the Magic scored yesterday, it was Nelson doing a lot of the damage. Paul Flannery noted that Nelson did damage when the C’s went under the screen, and he did. But he also did damage when the C’s went over the screen.

He’s surprisingly quick for a guy who kinda looks like a chunker and does a good job splitting the coverage to get into the middle of the lane. When he’s aggressive coming off the screen, it’s going to be tough for Boston. Because Nelson is a good shooter, Rajon Rondo has to defend him over the top of the screen, leaving the big man alone with Nelson. Being quick, skilled and aggressive, Nelson is able to attack big men, get penetration, and make plays.

Here’s a still picture of Nelson at the point of attack coming around the screen (yes, I know it’s against the Hawks — couldn’t find one of Nelson running p/r against the C’s). Even though it isn’t the C’s, the defense was very similar to how the C’s played it — a flat hedge by the big man, a trailing defender trying to get over the screen to no avail.

Nelson continues to attack the big man, isolating against him as the defender still trails the play. Even for a big man as mobile as Al Horford (or KG/Perk), it’s tough to stay in front of an attacking Nelson. The key is to make Nelson take a step backward, to give enough time for Rondo to get into the play. Horford fails to do that here, and Nelson is in the driver’s seat.

Though the Celtics were shredded by Nelson in the pick-and-roll, not all was bad. He finished with only 2 assists, so his influence was pretty much limited to his own scoring. The pick-and-roll didn’t help to get everyone else involved. It could start to pay benefits for all the other Magicians, though, should the Celtics not tighten up the defense.

Rondo has said on more than one occasion that Nelson is the most important Magician (at least on offense), and Game One showed why. Nelson is one of two Magicians (Vince Carter being the other — with apologies to J.J. Redick, who pretended like he could for parts of Game One) who can create their own shot or opportunities for others.

Look for the C’s to make an adjustment in Game Two, if they want to continue to stop the dangerous Magic.