WASHINGTON — Gio Gonzalez gave up five runs in the first inning of yet another concerning outing for a Washington Nationals starting pitcher, and the NL East champions wrapped up the regular season Sunday with an 11-8 loss to the Pittsburgh Pirates.

Gonzalez (15-9) needed 39 pitches across 16 arduous minutes to record the game’s first three outs, while his ERA rose from 2.75 to 2.96 just in that opening inning. The Pirates batted around as the lefty walked two batters, hit Jordan Luplow to force in a run with the bases loaded and allowed Max Moroff’s three-run double along with Jacob Stallings’ RBI single.

This came a day after 2016 NL Cy Young Award winner Max Scherzer left his last pre-playoffs start for Washington in the fourth inning after feeling something wrong with his right hamstring. At least Scherzer sounded optimistic about things Sunday, saying that an MRI exam showed he had only “tweaked” his muscle, not strained it.

Gonzalez wound up going only 4 1-3 innings, allowing six runs, seven hits and three walks. It was his shortest appearance of a bounce-back season after going 11-11 with a 4.57 ERA in 2016 and part of a downward trend of late: Four of Gonzalez’s last five starts lasted five innings or fewer. Only one other time all year did he depart that quickly, way back on May 3.

This time, Gonzalez left after serving up three consecutive hits in the fifth.

Just to introduce another element of uncertainty from a game that didn’t matter for either team, Tanner Roark — slated to join Stephen Strasburg, Scherzer and Gonzalez in Washington’s postseason rotation — entered in the sixth and promptly gave up two runs, three hits and a walk in his one-inning tuneup.

Hardly the preferred sort of preparation before facing the defending World Series champion Chicago Cubs in an NL Division series that starts in the nation’s capital in less than a week.

Washington’s hitters did not exactly look ready for prime time for much of the day, either: They went 0 for 7 with the bases loaded..

Angel Sanchez (1-0) earned his first big league win with two shutout innings in relief. George Kontos got the final out for his first save in 322 appearances in the majors.

The time of 4 hours, 22 minutes made this the longest nine-inning regular-season game, by time, in both Pirates and Nationals history.