The defenseman did not play in a 1-0 win against the New York Rangers on Saturday. He had one shot on goal and two hits in 19:02 of ice time during a 6-1 loss to the New Jersey Devils on Thursday.
Matheson was second among Penguins defensemen with 21 points (seven goals, 14 assists) in 50 games.
Mark Friedman, who was recalled from a conditioning assignment with Wilkes-Barre/Scranton of the American Hockey League, played 12:11 with one shot on goal Saturday.
"We thought it was very important that he get into some games," coach Mike Sullivan said Friday of Friedman. "That puts him into a better position to be successful when he gets the tap on the shoulder to play here in Pittsburgh. It's not an easy challenge for a player when he's been on the sidelines, so to speak."
Friedman had not played in the NHL since Jan. 8, when the Penguins used 11 forwards and seven defensemen in a 3-2 loss to the Dallas Stars. He last played as one of Pittsburgh's regular six defensemen Nov. 13. He has four assists in 13 games this season.
The Penguins (32-14-8) used the same six defensemen in 40 straight games.
Defenseman Pierre-Olivier Joseph was recalled from the AHL on Friday. He has no points in four games with the Penguins this season and 28 points (eight goals, 20 assists) in 40 AHL games.
