With Spring Training about to start, it's time for an in-depth look at the Pirates' roster. This is the final part of a series checking in on their current and future options at each position. Last, but not least: the outfield.
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The big question: Can they carry the lineup?
The Pirates believe pitching will be their strength, particularly at the front of the rotation and the back of the bullpen. But somebody will have to produce runs at the plate and prevent them in the field, and Pittsburgh's outfielders might be the best bet to do both.
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The Pirates' starting outfielders -- Corey Dickerson, Starling Marte and Gregory Polanco -- were three of their seven best players last season, according to Baseball-Reference's Wins Above Replacement. Dickerson (3.8 bWAR) hit .300 and won his first Gold Glove Award. Marte (3.7 bWAR) slugged 20 homers and stole 33 bases. Polanco (1.9 bWAR) finally broke out offensively, launching a team-leading 23 homers with an .839 OPS, before sustaining season-ending injuries.
Dickerson accomplished his goals last season by playing elite defense and significantly cutting down his strikeout total. Marte returned to the field for a full year after serving a PED suspension in 2017. Polanco overcame a few slumps and at times looked like a truly dangerous hitter.
But now Polanco needs to get healthy as soon as possible after September shoulder surgery, and offseason acquisition Lonnie Chisenhall needs to stay healthy while he's filling in as the regular right fielder. Dickerson will try to follow up his strong Pirates debut with an even better walk year. And Marte, 30, is still searching for a level of consistency that matches his incredible raw talent.
There are fewer questions facing the Pirates' outfield compared to their infield -- these players have proven their ability -- but there might be more pressure.

The Opening Day starters: Dickerson, Marte, Chisenhall
The Pirates are still reaping the rewards of the Rays' decision to designate Dickerson for assignment last February. The 29-year-old left fielder was a deserving Gold Glove winner last year, and his offensive numbers might have been even better if not for a disabled-list stint and a post-DL slump. He should hit in the heart of the order, although he thrived as a leadoff man during the Bucs' 11-game winning streak last July. He will reach free agency at the end of the season.
Dickerson's defensive breakout received most of the attention, but Marte matched him with 10 Outs Above Average as he took over in center field. Many of Marte's teammates believe the team goes as he goes, so perhaps it's no surprise that the Pirates struggled as Marte slumped through June and August but enjoyed their best month as a team while he slashed .341/.371/.635 in July. This is the final guaranteed season of Marte's contract, which includes affordable club options for 2020 and '21.
The Bucs are betting on good health for Chisenhall, the 30-year-old former Indians outfielder who signed a one-year deal in November. He has played only 111 games over the past two years due to calf injuries, but he hit at a high level -- .297/.368/.503 with a 128 wRC+ -- when he was on the field. Chisenhall says he is healthy and happy about the opportunity in Pittsburgh. He will be the regular right fielder until Polanco returns, then he could become a fourth outfielder or super-utility man given his versatility.
The DL watch: Polanco
The Pirates issued a broad time frame for Polanco's return last September, initially setting an estimate between mid-April and mid-June. The offseason has brought little clarity, but that should change as Polanco works through a throwing program this month to test his surgically repaired left shoulder. By all accounts, Polanco's rehab has gone well.
Polanco launched five homers in his first 11 games last season then fell into a deep slump. He took a step away from the plate in early June and hit .287/.361/.560 the rest of the way. He played 130 games before sliding his way into season-ending injuries on Sept. 7, an encouraging display of durability after an injury-plagued 2017 season.
Polanco's defense still leaves something to be desired, but he spent most of last season batting second or third for manager Clint Hurdle. The Pirates will need a lot of things to go right to contend this year; an early, fully healthy return for Polanco would be a good place to start.
Depth: Pablo Reyes, José Osuna, Patrick Kivlehan, JB Shuck, Nick Franklin
Reyes will compete for a bench spot after a strong September, and his versatility is probably his best asset. Osuna can handle a corner spot, and his right-handed power potential might be appealing considering three of the Pirates' top four outfielders bat left-handed. Pittsburgh brought in Kivlehan, Shuck and Franklin, all of whom have big league experience, on Minor League deals.
The Pirates are still open to adding more experienced outfield depth, so this list may grow.

In the pipeline: Travis Swaggerty, Calvin Mitchell, Jason Martin, Bryan Reynolds, Jared Oliva, Lolo Sanchez, Conner Uselton, Juan Pie
There is a decent amount of outfield depth and upside throughout the Pirates' system. It starts in Triple-A with Martin and Reynolds, who will return to big league camp after being acquired last offseason. Martin dominated Double-A last year then struggled in Indianapolis, while Reynolds bounced back from a fractured hamate bone to slash .302/.381/.438 for Altoona. If all goes well, both could make an impact late this season or early next year.
Swaggerty, the Pirates' first-round Draft pick last year, is the club's No. 3 prospect according to MLB Pipeline. The lefty-hitting center fielder should spend most of this year with Class A Advanced Bradenton and may move quickly through the system. The Pirates are also high on Mitchell, a second-round Draft pick in 2017 who slashed .280/.344/.427 as a 19-year-old at Class A last season.