RESPECT is the key word for Sam Jacobs ahead of his clash against Greater Western Sydney ruckman Shane Mumford.
 
Both have started the year in sensational fashion and are early tips to battle it out for All Australian selection.
 
Mumford monstered Carlton last weekend, finishing the game with 11 disposals and 47 hit-outs.
 
Weighing in at 105kg and once claiming that "he's always trying to hurt someone", Mumford is one of the League's most intimidating figures.
 
Crows ruck coach Matthew Clarke told AFL.com.au that Jacobs had to respect what Mumford was capable of, but he must also enter the game willing to match the Giant's physicality.
 
Clarke backed Jacobs to do exactly that; the 27-year-old only gives up about four kilograms to his opponent and has a slight height advantage.
 
Jacobs has proven himself a star in the AFL and Clarke suggested he keep it in mind on Saturday.
 
"In terms of that physicality we've just got to come with a competitive mindset and Jacobs is probably at the point in his career where physically he can handle the bigger guys a bit better than perhaps he had earlier in his career," Clarke said.
 
"We don't overplay it too much. We just go out to perform as we would on any other week.
 
"Just respect what he can bring to the contest and make sure that your mindset's such that you're able to match it."
 
Young ruckman Reilly O'Brien could well have received the call-up to help Jacobs this weekend had Josh Jenkins taken another week to return from a hip injury.
 
O'Brien was upgraded from the rookie list earlier this month after impressing in the SANFL.
 
In his first season playing against men, the 19-year-old is averaging 31 hit-outs and 13 disposals a game.
 
Like his teammate Jake Lever, O'Brien has a tough, competitive spirit that has him in line for an earlier-than-expected senior debut.
 
Coach Phil Walsh has already sung his praises and, although Clarke was quick to point out he had a long way to go with his development, the Crows see big things for the 201cm teenager.
 
"He's done really well – he got a go in the NAB Challenge which was great because it exposed him to the level and he held his own," he said.
 
"The competitiveness is there, he follows up really instinctively which is a great attribute to have and in the space of about six months he's really acquitted himself well.
 
"He's not the finished article just yet but he's got a real willingness to learn, he's really engaged and looking to improve his footy but also he hasn't been daunted by the challenge of going up against some of those bigger bodies."