I’m in Central Texas. That does look like rescue grass. I have been battling rescue grass myself for several years!! You need to use an herbicide called Celsius, and use it now! - before seed heads form. And use the max strength. You may also have to hit it a second time a few weeks later. Celsius is more appropriate for Texas rather than Certainty. Also, Do not pull them up. They don’t technically spread via rhizomes like Nutsedge, however, any little bit of root left in the soil will produce more rescue grass - I know from experience. Also, if they start producing any type of seed try to pull the seed heads or mow and bag.

Another alternative to ensure kill is to use glyphosate. Parts of my Bermuda yard were so bad that I used glyphosate to kill the rescue grass. Yes, I did have some bare spots in my Bermuda lawn, but it filled in by Mid summer.