Tim McGraw's 2015 Shotgun Rider Tour has come to an abrupt end, as doctors' orders have forced the singer to cancel the final two shows of his summer trek.

According to a post on McGraw's Facebook page, doctors have placed the singer on vocal rest. Therefore, his Sept. 18 concert at Shoreline Amphitheatre at Mountain View in Mountain View, Calif., and his Sept. 19 show at Irvine Meadows Amphitheatre in Irvine, Calif., have been canceled.

"This is so disappointing to me. We've had such a great summer, and I was looking forward to this final weekend with the fans in California," McGraw says in a statement. "I appreciate the support and look forward to coming back soon. The word 'can't' is just not in my DNA. If there was any way I could sing, I would do it."

Tickets for both shows will be refunded at their point of purchase. Chase Bryant and Billy Currington were serving as opening acts throughout McGraw's summer tour.

On Thursday (Sept. 17), McGraw officially announced a brand-new album, Damn Country Music, due out on Nov. 6. The regular edition of the record will feature 11 tracks, including collaborations with Big & Rich and McGraw’s daughter Gracie; the deluxe edition will have three additional songs.

“I think, as an artist, you have to go into the studio and try to reach the goals,” McGraw muses. “I think if you start chasing radio, if you start chasing what your fans want to hear — I think if you start chasing what you think is the end thing — it’s okay to include some of that stuff, but if you start chasing that as a home-base, I think you’re in trouble as an artist.”

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