The cancellations and postponements come weeks before his scheduled performance at Glastonbury.
The singer was slated to take the stage on Sunday night (June 1) as part of his Encore Shows run.
The gigs at the Colosseum at Caesars Palace will kick off later this year.
The total number of shows for the summer run is now up to 21.
The Encore Shows will continue at the Colosseum after Sir Rod hits the road with Cheap Trick on his One Last Time summer tour.
The fall run of shows will feature eight performances from October through early November.
The group tacked on a trio of shows in mid-August, bringing the total so far to 18.
Prep your all-white outfits, because the first pop group to take over the Sphere will play 12 shows in July and August.
The "Die With a Smile" singer will extend his stay at the Dolby Live at Park MGM through the spring and summer.
The 15 shows were scheduled to begin in February and run through May at Planet Hollywood's PH Live.
