Matthews has scored five goals in three games after missing 14 games with a left shoulder injury.
Forward Connor Brown said he is excited to see how Nylander will help the Maple Leafs improve further, even though they are 20-8-0 and are second in the NHL with 40 points without having Nylander in the lineup.
"Absolutely I think he'll be playing with some urgency, some hop in his step and it will be fun to see," Brown said. "He's a quality guy and a very, very good player. Any time you can add a player of his caliber to your team, you get better right away."
Nylander, selected by the Maple Leafs with the No. 8 pick in the 2014 NHL Draft, had 61 points in each of the past two seasons and has 135 points (48 goals, 87 assists) in 185 NHL games. The Maple Leafs have won five games in a row.
Nylander said he was glad to have been able to join the team in time for the visit to the Hospital For Sick Children, an opportunity he looks forward to being a part of each year.
"It's lots of fun to see the kids and to make their day, helping them get away from what's going on in their lives and getting them to appreciate something else for a little bit, it's big," Nylander said. "Coming here, you realize what other kids are going through and how tough it is. It's just nice to be able to take a moment out of your day to try to make their day a little better."