His former coach at Havelock North, Dione Adams, put him in touch with Frank Farina at Wynnum.
Farina is an ex-Socceroo and former coach of the Brisbane Roar and Sydney FC in the A-League.
"Through him I got a trial with the Wolves. I went to the trial and got the gig."
Germany was floated as a potential opportunity as well but, with the uncertainty of Covid-19, Grunwald opted to be in a place a bit closer to home.
"Halfway around the world with Covid, if it didn't work out I would probably be stuck over there."
He felt it was time to step out of his comfort zone and test himself with a higher level of competition.
"The quality of football here is really good. Training is a bit different to what it was, you have to fight for your spot every training. It comes with a little bit of pressure but, at the same time, it makes you a better player.
"It has been a bit hard being away from friends and family, especially over Christmas and New Year. I am settling in a bit now though."
He said a discussion with James Musa, Whanganui's best footballing expat who plays for Phoenix Rising FC in the US, helped inspire his next steps.
Wynnum signed Grunwald with the intention of him playing in an attacking role, using his athleticism and willingness to take on defenders to score goals and create opportunities.
"We play a nice style of football, setting up in a 4-4-2. We have some quality in the midfield and I'll be floating around up front.
"That's my preferred position these days. Scoring goals hopefully."
Grunwald said he was thriving in a more professional environment and looking forward to what the future held.
"You can see the road ahead and work towards that. I'm really blessed to be here. It has been a scary experience, turning up to trials as the new kid on the block. You just have to put yourself out there.
"My last two years in Whanganui really sparked my love for football again and that's where it all started."
Wynnum Wolves FC start their season on the first weekend in March.
To keep up with Grunwald's journey, you can follow the Wynnum Wolves FC Facebook page.