PORT Adelaide are the second club in a week to receive an AFL fine for having too many players on the field.

The league announced it had penalised Port $3000 for having 19 men on the ground at the start of the third term in the March 1 practice match against Collingwood at MC Labour Park.

"The club acknowledged the breach when contacted by the AFL and it was also corrected quickly on the day, when it occurred," the league said in a statement.

Last week, Hawthorn received a $7500 fine after Brent Guerra was their 19th man on the field early in the last term of their NAB Cup semi-final loss to Adelaide.