The more time Vasiliy Lomachenko and Oleksandr Usyk spend away from the ring to defend their country, the more it hurts boxing culture.

That was the substance of promoter Bob Arum’s message in a recent video put out by his promotional company, Top Rank Inc.

Both Lomachenko and Usyk have put their boxing careers on hold in order to focus on defending their homeland of Ukraine from Russia’s ongoing military invasion. Lomachenko, a former 135-pound titlist, and Usyk, the unified WBO, WBA, and IBF heavyweight champion, were out of the country, in late February, when Russian president Vladimir Putin launched an attack on Ukraine. Both boxers, however, quickly returned home and enlisted with the Ukrainian army.

The 90-year-old Arum, who promotes Lomachenko (16-2, 11 KOs) and is friends with Usyk (19-0, 13 KOs), gave a heartfelt message to the boxers, whose courage he admired, even if their absence signified a net loss for boxing fans.

"Sportsmen around the world, and particularly those of us in boxing, really miss seeing the outstanding talents of Vasiliy Lomachenko and Oleksandr Usyk inside the ring,” Arum said. “These are two of the premier fighters in our time and the fact that they are not performing now is a real sadness on our part. And hopefully we can see them back displaying their amazing talents in the near future.

Lomachenko and Usyk’s decision to take a step back from prizefighting has caused something of a rift in the boxing schedule.

Lomachenko was presumed to be the frontrunner to land a coveted fight against WBA, IBF, and WBO lightweight champion George Kambosos of Australia. Usyk was set to defend his belts against Anthony Joshua in a rematch of their meeting in September in London, which Usyk won by unanimous decision.

Both bouts no longer appear to be realistic possibilities for the near future. Eddie Hearn, the promoter of Joshua, said recently that Joshua may take up an interim fight in the meantime and try to land the rematch with Usyk, a former undisputed champion at cruiserweight, later in the year. Hearn also said recently that, with the temporary unavailability of Lomachenko, he has been focused on negotiating for his client, WBC lightweight titleholder Devin Haney, to face Kambosos.

The 34-year-old Lomachenko was last in the ring in December at Madison Square Garden in New York City, winning a wide decision over former lightweight titlist Richard Commey.

The 35-year-old Uysk won a unanimous decision against Joshua last September at the Tottenham Hotspur Stadium in London.