Don't Make Me Use The Bat
Omri flat out is not a guy that would fake an injury or go along with a plan to sit him with a phantom ailment. It's not part of his mental makeup.
Omri was a major component of the team in the locker room last year, but there was almost an unwelcome mat thrown out for him this year, and he has been on the outside looking in. They asked for a trade a month into the season. And for Omri a trade to the right team could literally be worth $10+ million. That's a lot of motivation to take it easy, and a "he's hurt" scratch is a lot better for his rep, trade chances, and FA chances, than a he's healthy but benched thing.