Portland veteran Egan has moved into defence in 2019 after building his reputation as a tough nut midfielder.

O'Brien, who has returned to the Kangaroos after a stint in the SANFL, is also playing across half-back, having previously spent time in the middle.

The pair will line up at opposite ends when the Roos host the Tigers in their annual Hampden league Anzac Day clash at Melville Oval on Thursday.

Egan, 32, and O'Brien, 24, said half-back was the ideal spot for an on-field leader to have an impact.

"I can use my voice better and that's one of the assets I have," Egan said.

O'Brien echoed Egan's thoughts.

"I'd like to think I am vocal on the field, that I can help the team set up and give instructions and give encouragment out to the younger boys," he said.

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Egan said his role change would benefit the Tigers' next generation.

He said it was exciting to see new players float through the midfield.

"It's good we have a few bigger bodies in there in Harris Jennings and Aaron Shepherd and Dylan Barr runs through there as well," Egan said.

"It's something we've lacked the last few years. We've been pushed off the ball.

"Harris has two best-on-grounds to start the year. He runs hard and is a beautiful kick of the footy.

"I do miss being in there but it's good to see the young fellas taking it on."

Egan, who is watching teenagers Sam Hampshire and Ed Pritchard develop in defence, said Portland was disappointed to lose recruit Daniel Sturzaker to a season-ending knee injury.

"He had osteitis pubis over the summer and his first night on the track he was warming up and heard his knee, a pop," he said.

"It was his ACL. He's had surgery but I think he's helping us on the bench."

O'Brien said he was adjusting to his spot across half-back.

"I should be running off a bit more but we've had two pretty hard games the first couple of weeks and you don't want to leave your man behind," he said.

"I am looking forward to developing my game and becoming more attacking."

O'Brien is relishing being home in the south-west.

He became a father for the first time three months ago and credits daughter Quinn for "making me more mellow".

"I read in the paper, one AFL footballer put it well. He said you can have stresses at work and footy and get caught up in it but the moment you walk through the door, you see your little girl and you hear her cries and it changes your mindset," O'Brien said.

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