THE AFL has admitted the umpires erred in awarding two of the five 50-metre penalties given to Carlton against Richmond for encroaching into the protected area, with another being assessed as a marginal call. 

Clubs were told over the pre-season the rule regarding the area around a player who has taken a mark or given a free kick would be enforced more strictly this season.

On Friday, they were informed that incorrect decisions had been made in the season opener. 

The protected area is five metres behind the player with the ball, and 10 metres either side of the player. 

The first mistake was against Shai Bolton just over a minute into the match, when Zac Fisher had the football 60 metres out from goal. The AFL said there was no evidence of Fisher's protected area being infringed upon.

WATCH: Bolton feels the umpire's wrath

Josh Caddy was also wrongly penalised when Charlie Curnow had the football about 55m out from goal in the third quarter.

WATCH: Caddy furious with 50-metre call

The marginal call happened earlier in the third term when Jacob Weitering had possession on the wing, against Kamdyn McIntosh. Weitering played on as he swung on to his right boot, which shortened the distance between the two.

WATCH: Kamdyn McIntosh's close call

In the umpire's opinion, McIntosh was "close to five metres away running through the protected area without deviating from his original line".

All umpires will be briefed on these decisions ahead of the rest of round one.

Richmond coach Damien Hardwick was philosophical after his side's 26-point win, which the AFL acknowledged in its statement.

"It's a rule, we understand that, and we've got some work to do on that part of the game," Hardwick said on Thursday.

"But if the rules are in play I'm very happy provided they are consistent, because that way we know what we're playing with.

"I thought we gave away too many cheap free kicks. We gave away seven goals from free kicks tonight."