Maloney, who was diagnosed with Focal segmental glomerulosclerosis (FSGS), a rare kidney disease, had a successful kidney transplant as did his sister, Lilly, who also attended the Senators game.
The siblings played a little floor hockey with Tkachuk and Daniel and the Senators captain did "The Worm" for a bit.
Before the game, the kids also met members of the Pittsburgh Penguins including captain Sidney Crosby, who gifted Daniel a stick.
Closer to game time, Daniel got to skate a solo lap and drop a few pucks into the net as the crowd cheered.
The Senators won the game, 5-4 in overtime. Tkachuk of course scored the winner.
"He's our lucky charm," Tkachuk said after the game. "For us to have him, I had a blast. To meet him and meet his sister Lilly. To see how much fun he had in the morning then see him buzz around there for warmups. It was amazing. It put a smile on all our faces. I feel like he's the reason we won tonight."