It was one or the other, and the Penguins chose the one they knew the best.

Rising tension reportedly forced the club to choose between two of their biggest stars as Evgeni Malkin and Phil Kessel could apparently no longer co-exist. So after a tumultuous season when the team got swept in the first round by the Islanders, Pittsburgh general manager Jim Rutherford traded Kessel to the Coyotes in June.

According to The Athletic, Malkin made the ultimatum after the Russian forward had one of the worst seasons of his to-be Hall of Fame career, mostly with Kessel on his wing — as he often was during their back-to-back Stanley Cup victories in 2016 and 2017.

“Malkin had come to believe Kessel was content with two titles and mostly interested in his statistics,” read the story by Rob Rossi, who traveled to Moscow to catch up with Malkin.

“Malkin was worried he’d be seen the same way if Kessel remained his winger. Multiple team sources say Malkin requested a trade if Kessel was to return. Malkin denies that, but it doesn’t mean he wanted to play another game, let alone another season, with Kessel as his linemate.”

Kessel had previously decided not to waive his no-trade clause when Rutherford had a deal in place with the Wild. But he did waive it to go to Arizona, where he reunited with former Penguins assistant coach and his confidant, Rick Tocchet, now the head man for the Coyotes. The Penguins sent the 31-year-old Kessel, along with a fourth-round pick and defenseman Dane Birks, to Arizona in exchange for center Alex Galchenyuk and defenseman Pierre-Olivier Joseph.

Kessel also had a rocky relationship with Penguins coach Mike Sullivan, the former Rangers assistant under John Tortorella. Malkin, too, had his issues with Sullivan, complaining about his ice time despite knowing that he his game had slipped. When Rutherford started dangling Malkin’s name in trade talks, that was also upsetting to the 33-year-old who has won three Stanley Cups, one Hart Trophy, one Conn Smythe Trophy, and two Art Ross Trophies.

“You lose confidence, and you start (to) think too much,” Malkin said. “I (started) to think too much. And when I start to think too much, I start to get mad at everyone.”