From a team release:

The Pittsburgh Penguins have recalled defenseman Joe Morrow from Wilkes-Barre/Scranton of the American Hockey League, it was announced by executive vice president and general manager Ray Shero.
Morrow, 20, will be looking to make his NHL debut Sunday night against New Jersey. The 6-foot-1, 204-pound blueliner has spent his first professional season with WBS, tallying 10 points (2G-8A) in 39 games played.

Morrow, who was drafted by the Penguins in the first round (23rd overall) of the 2011 NHL Draft, has posted two points (1G-1A) and a plus-5 rating over his last nine AHL games.

It's a curious move, because most have used phrases like "tearing down his defensive ame" and "needs a lot more work in his own zone" to describe Morrow's first professional season. Known as a gifted skater with good puck control, movement and shot, Morrow only has two goals and eight assists in 39 AHL games so far this season.

Morrow played a very good training camp in 2011, giving many optimism he'd quickly return to the NHL level. He definitely has all the physical tools to be an impact player, but it's important to remember he just turned 20 a couple of months ago and has a lot of growing still to do.