David Lee Roth has canceled all but one of his upcoming tour dates, with no reason provided for the change in plans.

Some reports speculate that a lack of ticket sales prompted this decision, leaving just one concert – in Sturgis, South Dakota, on Aug. 7 – on Roth’s public schedule.

The cancellations elicited a response from Roth’s Van Halen successor, Sammy Hagar, who expressed sympathy for Roth, praised him for maintaining the band’s spirit, and invited him to participate in his own band’s upcoming Las Vegas residency.

Fans of Van Halen may find Hagar’s message surprising given the historical tensions between the two singers over the years.

READ MORE: How David Lee Roth Out-Gonzoed Van Halen on Eat ‘Em and Smile

“Hey Dave, Sammy here,” he said in a Facebook video. “I just got a call from Michael Anthony about your tour getting canceled. I want to say from the bottom of my heart, I’m sorry. I hope you’re well and that there’s not a physical problem.”

He continued: “Mike and I love that you’ve been out there doing it, supporting the greatest band in the world that we were both part of… keeping this music alive.

“You and I, Mikey, Al, Ed cannot be replaced. So when you’re ready to carry on, you go, brother. Mike and I support you.”

Sammy Hagar’s Offer to David Lee Roth Is ‘From the Heart’

Hagar then extended his invitation: “Come to Vegas for the residency in September,” he said. “Come on, join us. Sing a couple of songs, MC the damn show. Come out and just do what you do – which is pretty damn entertaining!”

He concluded: “Anyway, hope you’re well. I really do. God bless, brother.”

The caption accompanying Hagar’s Facebook reel read, “I’m looking rough but who cares. … I’m serious with this post. I hope the news about Dave is not AI! If it is, my post is still coming from my heart and soul.

“It is so important that this music carries on, especially with AI music out there. Those of us who can still go out and play should do it as long as they can physically and emotionally carry that torch.

“Van Halen was, should be, and hopefully always will be real live music, not just for our fans but for future fans of real rock music.”