As I said, I think defenders were generally BETTER in Maradona's time at actual defending. Today, it is hardly allowed to tackle, so defenders are generally way worse at it. There are also other characteristics in defenders that are more desirable today such as functional technical level, good on the ball, decent passer and so forth.
Just go back to Adams, Keown, Winterburn, Dixon and Bould; as pure defenders, they were better than most of what we see today, and we had 5 of them at the same time. My argument is that not only were defenders better at defending when Maradona was playing, they also could get away with murder.
In general, I agree with Ev though that it is difficult to compare players from different eras. I hold Messi higher personally because he generally played with lesser team mates and still managed to drag teams to success.
