PHILADELPHIA — After a rainout in Syracuse, Blade Tidwell was finished for the day.

He was about to begin playing some “Fortnite” on Thursday night when his plans changed.

The pitching-desperate Mets burned Justin Hagenman’s arm in relief in their finale in Atlanta.

So at about 10 p.m., Tidwell was told he was starting Friday.

To make roster space for Tidwell, the Mets optioned Hagenman

“We just jumped in the car,” Tidwell mentioned, referring to himself and his girlfriend as they made the 4 ½-hour drive south, quickly gearing up for a matchup against one of baseball’s stronger offenses.

Tidwell was better, if not excellent, in an emergency spot start during a 10-2, series-opening loss to the Phillies at Citizens Bank Park.

After a May 4 debut in St. Louis went wayward — six runs in 3 ²/₃ innings — the 24-year-old prospect held his own over three scoreless innings.

He ran into trouble in a fourth inning he would not escape, perhaps a victim of circumstance.

For the first time all season, he was starting consecutive games on four days’ rest. He typically gets at least five days’ rest with Syracuse.

In his outing Sunday, he had thrown just 66 pitches. For that reason, manager Carlos Mendoza did not want to give him much of a leash.

In the fourth inning, singles by Nick Castellanos and J.T. Realmuto and a walk to Bryson Stott loaded the bases.

Tidwell skillfully prompted a ground ball from Otto Kemp, but the relay from Brett Baty to Jeff McNeil to Pete Alonso was just a bit too slow, which allowed the game’s first run to cross the plate.

After reaching 74 pitches, Tidwell was taken out, having given up four hits and three walks while striking out four. Jose Castillo took over on the mound and conceded one additional run.

“I thought the fastball had life. I thought the cutter, shorter slider, to go with the sweeper, was a lot better, as well,” Mendoza said.

Tidwell added: “It went better than the last, but there’s still work to be done.”