PITTSBURGH -- The first three weeks of the season, a shutdown pitching staff kept the Pirates close in nearly every game they played. Lately, a hot-hitting offense has made them competitive amid a brutal stretch for their rotation and bullpen.

The Bucs pitched well enough to keep it close and hit enough to make it interesting, but the defense let them down in a 5-4 loss to the Tigers on Tuesday night at PNC Park.

Top prospect Mitch Keller and third baseman Jung Ho Kang committed costly errors that led to a pair of runs in the fourth inning, and second baseman Adam Frazier misplayed a potential double-play grounder in the eighth inning. In losing 20 of the last 28 games, Pittsburgh has too often struggled to cobble together a winning combination of hitting, pitching and defense.

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“You need to play complete games to win at this level. Sometimes it’s hard to win when you don’t,” manager Clint Hurdle said. “That’s kind of where we’re at right now. More often than not, we need to put all three components together.”

The Pirates rallied to tie the game in the seventh thanks to key hits by pinch-hitter Colin Moran, who punched a single to left field with a runner on third, and leadoff man Kevin Newman, who laced an RBI triple into the right-field corner that tied it at 4. It was business as usual for a group that has averaged 5.4 runs per game despite the club’s 8-20 record over the last month.

“We’re all out there trying to fight for each other,” Newman said. “It’s cool when that’s the feeling behind your offense. We’re going to keep coming to the field and doing what we can do.”

That allowed Hurdle to bring in setup man Kyle Crick in the eighth. Crick put three runners on with one out -- Nicholas Castellanos on a walk, Miguel Cabrera on a single and Christin Stewart on a replay-overturned hit-by-pitch. Up came Brandon Dixon, who slapped a ground ball past Crick and toward Frazier.

Frazier fielded the ball cleanly. Rather than flip the ball to Newman at second base to start a potential 4-6-3 double play, Frazier moved to tag out Stewart. But as Stewart slowed down, Frazier instead decided to throw the ball to first baseman Josh Bell. The Pirates got one out, but Castellanos scored the go-ahead run.

“I think we had a chance to turn two conventionally,” Hurdle said. “I think we had a chance to shovel it to second and turn the ball back to first base. … There’s a play to be made there, and I don’t think that’s the one. Sometimes things happen -- you may change your mind in the middle of a play.”

Pittsburgh rallied again in the eighth, loading the bases with two out. But pinch-hitter Corey Dickerson grounded out despite hustling down the line, and a replay review confirmed the call. The Pirates put two runners on with one out in the ninth, but Bell hit into a game-ending double play. The Bucs finished 1-for-10 with runners in scoring position and stranded nine runners while falling to 26-17 when scoring at least four runs in a game this season.

“It’s a combination of things, and that’s why you continue to try to take care of what’s going on now, continue to coach them up and get them better,” Hurdle said. “We didn’t play well enough to win tonight, at the end of the day.”

Keller completed five innings for the first time in a Pirates uniform, struck out six and allowed only four hits. It was inarguably a step forward for the 23-year-old right-hander, but he was done in by a handful of mistakes -- some on the mound and two in the field.

After giving up six runs in the first inning of his Major League debut and three runs in the opening frame last week in Atlanta, Keller survived a 25-pitch first inning on Tuesday without allowing a run.

“Definitely better than the first two,” Keller said. “Just executing pitches and keeping at them and not giving in.”

Bell spotted Keller an early lead by blasting his 20th home run of the season out to center field in the second inning. But Keller gave back the lead in the third when he was one pitch away from getting out of it. He struck out the first two batters of the inning, walked Niko Goodrum with two out, then surrendered back-to-back RBI hits to Castellanos and Cabrera.

“That’s frustrating,” Keller said. “I didn’t hit my spot, and [Castellanos] made me pay for it. That’s frustrating.”

The Pirates’ defense came up short in the fourth. After a leadoff single, Keller threw away Harold Castro’s sacrifice bunt attempt to put two runners in scoring position. Then, catcher John Hicks slapped a grounder past Kang, bringing home both runners. Kang was charged with an error, one of three for the Bucs on the night.