"Zombie" blades of grass in my Marathon II sod (image attached)
Over the last couple of months, I have noticed these light-green colored blades of grass sprouting up in various places throughout my Marathon II covered lawn. Whereas 95% of the yard is lush and dark, I have about 4 small areas of "zombie grass" (I used the word "zombie" because it's looks like a grass/weed experiment gone wrong, not to mention its color is almost a neon green). I am not sure if they are weeds, hybrid grass, etc.. I've removed the zombie grass in some places and reseeded, but another patch will appear elsewhere sometime later.
Can anyone tell me 1) what it is...and 2) how do I prevent/remove it permanently?
Any and all insight and help is GREATLY appreciated. Thanks.