McKendry was signed by the Penrith Panthers in 2006, having initially been spotted by the Parramatta Eels.[3] He played for the Panthers' in their 2007 Jersey Flegg Cup Grand Final-winning team against the Eels, scoring a try.[4] Making his NRL debut for the Panthers in round 10 of the 2008 season, McKendry primarily played in the NYC for the Panthers between 2008 and 2009, for a total of 44 matches.[5] He moved into the Panthers' NRL squad in 2010.
McKendry missed the end of the 2016 season due an anterior cruciate ligament (ACL) knee injury, and the entirety of the 2017 season after re-injuring it during a pre-season trial against the Parramatta Eels.[6][7] McKendry returned to the NRL in 2018 but once again injured his ACL, against the South Sydney Rabbitohs in round 2. He stayed on the field for 13 minutes after initially going down, before the extent of the injury was revealed during the following week.[8]
On 16 September 2019, it was revealed that McKendry was one of ten players to be released at the end of the season by the Penrith club.[9]
On 29 November 2019, McKendry announced his retirement as a player from the NRL. McKendry broke the news via his Instagram page saying "I've spent the last 13 years with Penrith doing what I love as a job and got to live out my dream. My career didn't end as I planned due to consecutive ACL injuries but I never let injury force me into medical retirement and fought back each time to retire on my own terms. It's been one hell of a journey and it wasn't always easy but I wouldn't change a thing, my footy days are not over completely though as I have agreed to play with St Mary's in 2020, looking forward to running around with the boys".[10]