Note: With the exception of the goalkeepers, who were assigned the traditional shirt numbers for the role (1, 12 and 22) the Italian team was numbered alphabetically within their respective positions – Defenders (from 2 to 8), Midfielders (from 9 to 15), Wingers (16 and 17) and Forwards (from 18 to 21).
Jan Jongbloed wore number 8 because some of the players who had been in the Dutch squad at the 1974 FIFA World Cup, where the Netherlands used a purely alphabetical numbering system, were given the same numbers again in 1978. Hugo Hovenkamp withdrew from the squad before the tournament began, but after the deadline for naming replacement players had passed. The Netherlands thus went to the World Cup with only 21 players.
Each national team had to submit a squad of 22 players. All the teams included 3 goalkeepers, except Mexico who only called two.
References
^Tarantini left clubless after a contractual dispute with Boca Juniors, six months before the World Cup. [1]
^Hugo Hovenkamp withdrew due to injury. As the deadline for calling up replacement players had passed, the Netherlands went to the World Cup with 21 players only.
^Willie Johnston was sent home for failing a drug test after the first match against Peru.[2]