Messi is definitely a great player, however to compare his goals record with Maradona is difficult.

Diego played in an era when the offside rule was stricter, he also played his best years in Italy, the football was very defensive in Serie A in the 80s and 90s.

Maradona also didn't play with many great players in the Napoli side, whereas Messi is surrounded by amazing players.

In 1990 the offside rule was changed to adjudge an attacker as onside even if level with the second-to-last opponent.