ADELAIDE ruckman Sam Jacobs doesn’t want to see the 'third man up' at ruck contests banned, but is keen to see the rule "tweaked".

Jacobs told reporters in Adelaide on Thursday he would like to see teams able to block the run of players who intervene in ruck contests. 

"You can't just allow players to have a free jump into you," Jacobs said.

"If a third man is going to go, then you should be able to block his run and it not be a free kick. 

"I'm a bit of a traditionalist and it's obviously a tactic that's used against bigger ruckmen, or dominating ruckmen.

"I wouldn't like to see it ruled out altogether, but it definitely can be tweaked."

Senior coaches discussed whether to allow or ban 'third man up' in ruck contests at an AFL laws summit meeting in November. 

The incidence of players going 'third man up' at stoppages has increased dramatically in the past two years from 8.5 per cent in 2014 to 13.2 per cent last season. 

"It's more for those bigger guys like (Fremantle ruckman Aaron) Sandilands or if (West Coast ruckman) Nic Naitanui is going well or big (Melbourne ruckman) Max Gawn," Jacobs said. 

"We've seen Jordan Lewis with Hawthorn and the Kangaroos use it a lot in the past.

"Geelong is another team that has started to it a bit more, but it's not really common.

"We've used it at times.

"At other times, other teams have used it against us, depending on the opposition." 

Jacobs is one of the most durable ruckmen in the competition.

He has missed just three games in his six seasons with the Crows since coming across from Carlton. 

He will play his 150th AFL game if he takes the field against Greater Western Sydney in round one next season.

The ruckman missed two games with an ankle injury late last season, but says he has recovered fully over the break. 

"Having eight weeks off I was able to get some strength through the ankle again and I'm really confident it won't hamper me going forward," Jacobs said.

Jacobs has played a lone hand in the Crows' ruck division, but his back-up Reilly O'Brien was impressive when he made his debut last season. 

"He's put on a lot of size and I really welcome the competition between us," Jacobs said.

"I think it's great to have multiple options. 

"By no means am I comfortable that I'm going to roll into round one and my position is going to be there.

"He's going to make me better as well."

Jacobs was at Adelaide’s Rundle Mall helping to launch the Motor Accident Commission’s 2016 Christmas road safety activation initiative.