THE playing future of Collingwood forward Anthony Rocca is in doubt after he seriously injured an ankle yesterday.

The injury occurred during the third quarter as he kicked the ball, which caused pain where he had had a screw inserted in his ankle in his most recent operation. Rocca snapped his Achilles tendon in 2005.

Rocca's injury compounded the earlier loss of key forward Ben Reid in the first quarter to a broken foot, leaving the Pies with just two on the bench for most of the second half.

The serious injuries prompted Collingwood coach Michael Malthouse to call for an enlarged bench exclusively for players unable to return to the field due to serious injury.

"Both boys who came off aren't too good so we will have to wait and see. I am not going to start making predictions," Malthouse said. "Neither of them are what you would call available next week I would imagine.

"It is not Anthony's Achilles. It is roughly where the screw went into his ankle after the last operation, that is where he is sore. And Ben looks like he may have broken his foot.

"I think it was Terry Wallace that said there is almost a case for the bench being enlarged for just injured players and I guess you have to be able to convince the powers that be that you have got a legitimate injury; the player can't come back on; that you can't have those players there for just an interchange.

"I think there is a lot of substance to that. When members pay their money they want to see a team win lose or draw play with an even playing field.

"It's very difficult to win with 20 players these days because it throws your whole lot out. We lost Ben very early; we lost Anthony in the third quarter so it cut us down.

"I have no doubt today we didn't have the flexibility to hold on or get back in the game to put pressure on them but that is luck of the draw under the rules."

Malthouse said the change could be made at each quarter break and not during play and it would doubtless require the introduction of an AFL official to determine a player's fitness.

"I pushed 20 years ago to have four on the bench … I have been saying now for longer than 10 years we are one of the few team sports that has 18 on the field and has a ratio of only one to six. This is a contact sport, I really can't see why we can't add to our bench and in fact I can't even see why you need a second side — that is your roster you should be able to get through with that roster. You don't want 22 on the bench but we should be able to do more than hope you get through because it is only in hope."

When Rocca went off the ground Collingwood led by 23 points, but the Dogs piled on five of the next six goals to take a lead into the final break.

Collingwood led by 10 points at half-time but should have been further ahead after missing numerous shots at goal. Rhyce Shaw and Tarkyn Lockyer each missing three fairly regulation shots each before half-time.

Malthouse admitted inaccuracy hurt his team but was dismissive of the issue saying players did not intend to miss shots at goal.

Bulldogs coach Rodney Eade admitted remaining in the top four was his side's priority now that a place in the eight was assured.

He said he was frustrated with a poor skill level yesterday but praised the work and fight of the leaders in the team, Matthew Boyd and Daniel Cross, in rallying the Bulldogs and leading the team out of trouble.