Messi has scored 74 goals for Barcelona and 12 times for Argentina this year. Mueller scored 85 for Bayern Munich and West Germany.
Messi scored 73 times for Barcelona in the 2011-12 season, passing Mueller's milestone of 67 goals for Bayern Munich in 1972-73. He also established a Spanish league record of 50 goals last season.
Messi is a finalist for the FIFA's world player of the year award.