At Wimbledon, Federer announced he would not be playing in Montreal in a bid to rest ahead of the US Open.
Federer’s last appearance at the event came in 2017 when he was beaten in the final by Alexander Zverev.
And Hale says they had to respect Federer’s decision to skip next week’s event.
“It’s a shame we can’t have Roger in this edition,” he told Tennis World.
“But it is a decision that has been taken and that we have to respect [it].”
Next year, Federer may opt to miss the event again as it comes very quickly after the 2020 Olympics in Tokyo.
Federer is yet to officially confirm his desire to compete in Japan but is likely to play in potentially his last Olympics.
However, Hale believes Federer is capable of playing for at least five more years, with retirement not on the horizon.
“He loves to play here, and I am convinced he will play again one more time,” Hale said.
“I think Federer can have about five more years left at the highest level.”
Federer is not the only high profile name not playing in Montreal, with Wimbledon champion Novak Djokovic and Juan Martin del Potro withdrawing.
“I’m sorry to announce that I decided to pull out of Rogers Cup,” Djokovic said in a statement.
“With the support of my team, I have decided to give my body longer rest and recovery time before coming back again to play.
“I love Canada and I have many friends there that always make me feel like I’m at home and I’m looking forward to coming back again to play in front of all of you in Montreal.”
In the absence of Djokovic, Rafael Nadal is the top seed ahead of Dominic Thiem and Alexander Zverev.
It’s the Spaniard’s first tournament since losing to Roger Federer in the semi-finals at Wimbledon earlier this month.
Nadal is expected to arrive in Canada later this week and have his first practise session on August 2.
The first round of the Rogers Cup begins on August 5.
