Oar will likely become the Brisbane club's first choice player on the left side of the attack when the 36 year-old German leaves the club at the end of season.
The 25 year-old will also become one of the club's two marquee players next season, replacing Broich, with Oar stating that management's decision was part of the nature of football.
"It's just the nature of football. It's happened to me at other clubs as well," Oar told AAP.
"And we've shown this year we can both play in the same team, so I don't think it's me pushing him out the door, so to speak.
"This year Thomas has played different roles - so have I - and we've actually played quite well together, even last week against Wellington.
"There's always going to be questions asked about players who play the same position but from my perspective, I don't really see it that way.
"He's obviously a great guy, I've become quite good friends with him since I came back to Brisbane and he'll be missed on and off the pitch."
Broich is regarded as one of the best players to have ever played in the A-League, and Oar admits filling the two-time Johnny Warren Medal winner's shoes will be a tough task.
"For sure, they're big shoes to fill," he said.
"Hopefully next season I can come to the party and do whatever I can to replace what we'll be missing."
Roar now have even greater incentive to reach the A-League final and give Broich the ultimate swansong to his Brisbane career.
"That would be a great way for him to go out. The boys owe him everything we can give to maximise the chances of that happening," Oar said.