Joe Schoen joked in April that he was already fretting about four starters in the Giants secondary reaching free agency at the same time in 2028.

That’s a rich man’s problem compared to the poor reality emerging a few months later that the embattled general manager’s handpicked secondary — made up of four premium draft picks and two high-priced free agents, all 26 years old or younger — has vastly underwhelmed.

“The whole big picture, two things have happened,” secondary coach Marquand Manuel told The Post. “Not executing in the time that you need to execute, whether it be [a] penalty or not doing your job in the critical moments. And then injuries — next man up. Every team has them.”

With all the attention paid to pass rushers Dexter Lawrence, Abdul Carter and Kayvon Thibodeaux combining for just 3.5 sacks, it has flown under the radar that the Giants rank No. 22 in passing defense (225.2 yards per game) and the secondary has contributed just three interceptions and two forced fumbles in 11 games.