A blood clot found in Dupuis' lung ended the 36-year-old's season shortly after it was announced Maatta would undergo surgery to remove a cancerous tumor from his thyroid gland.
Maatta returned from the surgery on Nov. 18, after last playing against Buffalo on Nov. 1, but suffered an upper-body injury against Ottawa on Dec. 6 that ended his second NHL season.
''Dupuis, last year, I appreciated everything he did,'' Penguins coach Mike Johnston said. ''He worked right to the end to try to be ready for us if we extended our playoff series long enough so that he'd have a chance to get back in. Olli Maatta has had two bad injuries since he's been here, but we couldn't have a more positive young guy.''
Dupuis has been Pittsburgh's vocal leader for several seasons, but the forward's presence has been missed over the past two. His 2013-14 season ended after 39 games because of a torn ACL sustained against Ottawa on Dec. 23, 2013.
In his first game back from the injury, Dupuis had a goal and three assists in a season-opening 6-4 win against the Anaheim Ducks on Oct. 9, 2014. His former spot alongside Sidney Crosby on the Penguins' top line could be unavailable with newly acquired forward Phil Kessel expected to play first-line right wing, but Dupuis feels fortunate to join the team in any capacity.
''I haven't been on the ice for a while with a group of guys that are on the same team,'' Dupuis said. ''So, it was exciting. It was fun to be out there Last year, form November on, I was skating by myself before everybody and just the fact that I'm here and can go on the ice at the same time as everybody and just the fact that you're sharing the same thing as everybody else, you're going on the ice and you're practicing, you're battling It's good to be a part of that same group and not be the outsider looking in.''
The 21-year-old Maatta is expected to join Kris Letang, who is returning from a season-ending concussion, on Pittsburgh's top defensive pairing entering his third season. After impressing with nine goals and 29 points in 78 games as a rookie in 2013-14, Maatta experienced a frustrating freshman year.
The defenseman said he is prepared for the increased workload against opponents' top lines despite any potential rust he could experience.
''You just have to get your mind into it,'' Maatta said. ''It's mental too. It's not all about how the shoulder actually is, it's about mentally, you have to get over the hump.''