presumably he strained/bruised a hip flexor against SF, the Dolphins have been tight with the details Coach gave this comment
'It's not a case of a bruise (for Tua), that would be pain tolerance. Tua wishes it was a pain issue. It is quite literally being able to have the strength to do what we ask him to do as well as protecting himself from a very serious injury if we don't treat it appropriately.
'I wouldn't say it is a bruise but it is kind of a unique muscle issue.'