Both defenseman will now report to Wilkes-Barre/Scranton where the baby Pens are currently battling the Syracuse Crunch in the AHL Eastern Conference Finals.
The series is tied at one after two games thus far.
Harrington and Maatta are coming off their second consecutive Ontario Hockey League title with the London Knights and will now hope to make a positive impact towards Wilkes-Barre/Scranton claiming their own champi0nship.
Harrington, 20, was drafted by Pittsburgh in the second-round (54th overall) of the 2011 NHL Entry Draft and captained the Knights this past year.
This season with London, Harrington registered 19 points (3G, 16A) in 50 regular-season games and skated to a phenomenal plus-21.
He potted four assists (17 games) in the playoffs.
Maatta, 18, was drafted by the Pens in the first-round (22nd overall) and is probably the more intriguing of the two.
Logging 38 points (8G, 30A) in 57 regular-season contests, Maatta led all Knights’ defenseman in scoring and skated to a plus-9.
He continued his tear in the postseason – adding 14 points (4G, 10A) in 21 playoff games.
The baby Pens next game is Wednesday at 7 p.m. in Wilkes-Barre.