The Penguins acquired Kessel, 28, from the Toronto Maple Leafs on July 1, 2015, with forward Tyler Biggs, defenseman Tim Erixon and a second-round pick in the 2016 NHL Draft in a trade for defenseman Scott Harrington, forwards Kasperi Kapanen and Nick Spaling, and two draft picks.
Rutherford also said he is optimistic that other injured Penguins, including defensemen Trevor Daley (broken ankle) and Kris Letang (foot), and forwards Bonino (elbow infection), Bryan Rust (hand), Patric Hornqvist (hand) and Evgeni Malkin (elbow), will be ready to play against the Capitals.
Malkin (Team Russia) and Hornqvist (Team Sweden) will compete at the World Cup of Hockey 2016 beginning Sept. 17 in Toronto.
"All the injured guys are tracking in the right direction," Rutherford said. "Until they all get here, we won't know 100 percent where they're at, but it sounds like all the guys should be ready for camp.
"You always have a concern about the recovery period. Are guys 100 percent ready to go? They may be right at the start of the year and then you hit a little lull. But teams are going to do that anyways. I think that with our depth, we should be able to work our way through it."