"I'm not an owner," Harper said when asked if Klentak should return in 2021, according to Matt Breen of The Philadelphia Inquirer. "I'm glad I don't have to make those decisions."
Klentak is under contract through the 2022 season. However, the team has failed to make the playoffs since he joined the organization in October 2015. The Phillies are 326-382 with Klentak as the general manager.
The 40-year-old executive is responsible for Harper's 13-year, $330-million contract.
Philadelphia hasn't lived up to the hype as a World Series contender over the last couple of years despite high-profile and expensive free-agent additions such as Harper, Jake Arrieta, Andrew McCutchen, David Robertson, and Zack Wheeler.
Klentak also landed All-Star catcher J.T. Realmuto in a trade. Harper would like to see the soon-to-be free agent return to Philadelphia.
"J.T. Realmuto needs to be our catcher next season," Harper said. "Plain and simple. ... I don't think that should even be a question."
The Phillies missed the postseason for a ninth straight campaign by losing to the Tampa Bay Rays on the final day of the regular season. Philadelphia would've punched its ticket to the playoffs with a victory as the Milwaukee Brewers and San Francisco Giants lost Sunday.