On 8 May 2012, out of contract with Ässät, Rendulić agreed to a try-out contract with fellow Liiga club, HPK. With a developing, larged-framed body, Rendulić's initial trial with HPK was successful, earning him a one-year contract on 31 August 2012. In the 2012–13 season, Rendulić predominantly played with HPK in a depth forward role to finish with eight goals in 37 games.
