PITTSBURGH -- The A’s nearly closed out their nine-game road trip with a series win Sunday at PNC Park, but fell, 5-3, in the 13th as the Pirates rallied against reliever Fernando Rodney, capped by a three-run, walk-off homer from Starling Marte.

“Been through some tough ones here recently,” manager Bob Melvin said. “This one’s probably at the top.”

Frankie Montas went six strong for the A’s, allowing just one run, then Lou Trivino, Joakim Soria, Ryan Buchter and Yusmeiro Petit combined for six scoreless innings in relief.

That allowed Oakland to reach the 13th, in which Kendrys Morales knocked in the go-ahead run and Stephen Piscotty plated an insurance run with a double. But Rodney was taxed for three hits and a walk while recording just one out in the bottom of the frame.

• Box score

Oakland returns home with a 1-8 record on the road trip. The club is now 5-13 on the road; in 2018, the A's were road warriors, going 47-34 away from the Coliseum.

So what’s looking up for the A’s as they head back home, and what needs improvement?

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Starting pitching

Montas’ one-run outing was another link in a chain of strong outings by the A’s starters in Pittsburgh. Brett Anderson rebounded from a six-run start in Toronto on April 27 to record a six-inning, one-run start on Friday in a blowout win. Though Chris Bassitt gave up three runs on Saturday, all three came to one batter (Josh Bell), and he limited the Pirates’ bats otherwise.

Morales’ bat

After being acquired by the A’s on March 27, Morales struggled to produce out of the gate, with just 12 hits in his first 26 games, despite leading the team in hard-hit rate heading into this weekend’s series.

In three contests at PNC Park, Morales finally broke through. He went 7-for-13 with a triple and four runs scored. Though his spot on the field is up in the air with the impending return of Matt Olson (right hamate bone) from the injured list, the A’s have to be encouraged by Morales’ success.

Soria, Trivino

Soria’s two perfect frames with two strikeouts on Sunday were a boost of confidence. He pitched four shutout innings in his three outings on the road trip after beginning the year with nine runs allowed over 7 1/3 innings.

If Blake Treinen’s elbow soreness develops into something requiring time on the injured list, the A’s can also be confident in Trivino at the back end of the bullpen. He threw two scoreless innings on Sunday and has given up runs in only one of his 14 outings this season.

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Clutch star power

Khris Davis has hit a power snag of late, as he hasn’t swatted a homer since April 12, when he recorded his 10th of the year. However, Davis still found other ways to contribute, going 7-for-32 on the nine-game trip with two doubles and six walks.

On the other hand, Matt Chapman slugged well on the trip with five doubles, a triple and a homer. But his success only plated four runs, and he ended the stretch with an 0-for-5 game on Sunday.

Rodney, Wendelken

Outside of his performance in Friday’s blowout win, Rodney has struggled a bit of late. He issued three walks and four hits, including Marte’s homer, across his other three outings on the road trip.

J.B. Wendelken faced his roughest stretch of his A’s tenure over his past two outings, giving up seven hits and three walks that created six runs over 1 2/3 innings.