Rotor with the ridge more than likely needs replacement. The other might be ok, but both need to be 'miked' for thickness. Rotors are so inexpensive for the ML...I would be tempted to replace rotors and pads and be done with it.
DIY and save big bucks on both discounted parts (not list, like shops charge) and of course labor. Lots of good info on this site for changing out rotors/pads......