Strait made it through two songs Saturday night at the Sprint Center before telling the crowd he couldn't keep going because he was ill. The Kansas City Star reports the singer's voice was labored and hoarse.
Many of the 18,000 in attendance stood and gave him a rousing ovation after they got over their initial disappointment.
Martina McBride opened for Strait with a one-hour set, and she says she will be back next Saturday to open for him again.
All tickets for the first show will be honored at the March 3 concert.