I think RW has been one of our weakest positions for years - I genuinely struggle to think of the last decent player we had on that side. I also think adding a player like Mahrez who is good for 10-15 goals, and brings an assload of creativity, would really take the pressure off our striker problem. I don't know if he was ever available, or if a deal was ever likely, but he would be a great great fit for us if we'd have been able to bring him in.
Things are look pretty desperate at this point, if we do manage to sign Mustafi that should take care of our CB problem, but I just don't see a striker out there thats going to plug the gap.