A week ago, the Buffalo Bills suffered one of the most heartbreaking losses in franchise history, finishing on the wrong end of that epic 42-36 overtime playoff result against the Chiefs. 

On Friday, the Bills absorbed another gut punch when the Giants hired their 46-year-old offensive coordinator Brian Daboll to be the 20th head coach in franchise history. 

It’s difficult to measure which of those voids will affect the Bills most — that killer divisional playoff loss in Kansas City or the departure of Daboll, who has been so integral in developing quarterback Josh Allen. 

This much is certain in the wake of this blockbuster, double-franchise-turning transaction: The Bills’ loss is the Giants’ gain. 

“I feel like he’ll be a great fit for New York,’’ Bills star receiver Stefon Diggs told The Post over the phone on Saturday. “They’ve got some good pieces there already and he knows how to get guys the ball.’’ 

How does Diggs, whom the Bills acquired from the Vikings before the 2020 season, thinks Daboll’s coaching style will work when he’s the CEO of an entire roster? 

“As far as being a head coach,’’ Diggs said, “I think it’ll translate magnificently.’’ 

The word “trust’’ kept coming up from Diggs regarding what sets Daboll apart. 

“He has that great relationship from players-coach kind of thing,’’ Diggs said. “He trusts his guys. He trusts his players to make plays. When you have a coach like that, you want to play well for him. You don’t want to let him down because he puts so much trust in you.’’ 

Diggs then wanted to make one thing perfectly clear to the Giants locker room Daboll is about to oversee: Don’t mistake his player-coach way for weakness. 

“I can tell you first-hand that Brian Daboll will never let anybody walk over him,’’ Diggs said. “He’s cool, but he ain’t that cool. He’s a tough guy. He’s going to be hard on you. But he’s going to give you that rope and tell you he trusts you. 

“You want to play for those guys, because you’re like, ‘OK, my coach trusts me, I’m going to put that extra time in, catch a couple extra balls, watch 30 more minutes of film.’ That’s the kind of relationship you want with your coach.’’ 

Diggs raved about Daboll’s fertile offensive mind, comparing him to Chiefs head coach Andy Reid “and those guys that draw it up in the dirt, draw it up on their hand.’’ 

“He’s not a robot,’’ Diggs said. “He shows you that it’s OK to be creative and innovative.’’ 

In no place has that shown itself to be truer than with Allen. Daboll and Allen were attached at the hip since both got to Buffalo in 2018. Since the moment of their arrival to Western New York, Daboll helped take Allen’s raw talent and develop him into one of the best quarterbacks in the game. 

Allen’s completion percentage went from 52.8 percent in 2018, to 58.8 in 2019, to 69.2 in 2020. It was at 63.3 percent this past season. Allen threw 30 touchdown passes on his first two seasons and has thrown 73 the past two years. 

Those numbers didn’t improve through osmosis. 

“I wasn’t here in the earlier stages of his career, I’ve only been here the last two years, but when I got here they were talking all this stuff about Josh that I had never seen — that he was inaccurate and made bad decisions,’’ Diggs said. “And I’m like, ‘Damn, when I play with him, I don’t see that.’ He has a strong arm, he has a lot of confidence and he’s a tough quarterback. 

“Developing an All-Pro quarterback is not easy, and Dabes has had a lot to do with his development.’’ 

Diggs, too, praised Daboll for developing him into the receiver he is now. In his five seasons with the Vikings before the Bills acquired him in 2020, Diggs’s career high for receptions in a season was 102. 

In his first season with the Bills, he led the NFL in catches with 127 and yards with 1,535. He had 103 catches for 1,225 yards and 10 touchdowns this season. So, Diggs has had the best two seasons of his seven-year career working with Daboll. 

“I felt like when I got to Buffalo, he made me exceptional,’’ Diggs said. “That’s my guy forever. When I tell him that I love him, I mean it because I really appreciate all he’s done for me.’’ 

It makes you wonder what Daboll’s system will be able to do to unlock Giants receivers Kenny Golladay, who was an utter disappointment as a 2021 free-agent signing, Sterling Shepard, Kadarius Toney and Darius Slayton. 

Diggs said he can’t wait to see where his former coach takes this opportunity of a lifetime after 21 years toiling as an assistant coach. 

“I’ll be watching from a distance,’’ Diggs said. “I want great things for him.’’