PITTSBURGH -- The Pirates have had a busy offseason, overhauling a quarter of their 40-man roster. They revamped the bottom of their rotation, swapped Pedro Alvarez for John Jaso at first base and continued to add depth to the bullpen.
Still, some of Pittsburgh's biggest improvements in 2016 may come from within. While general manager Neal Huntington acquired several players looking to bounce back from injuries or down years, six returning Pirates also have room to improve this season.
• Around the Horn: Starting rotation | First base | Infield | Outfield
In the first part of our Spring Training preview series, let's look at which Pirates are on the rebound in 2016.
2B/3B Josh Harrison: After a breakout season in 2014, Harrison suffered through a season-opening slump and an ill-timed left thumb injury last year. His average dipped to .173 on May 10, then everything fell into place. Harrison batted .338 with an .811 OPS from May 12-July 5, before heading to the disabled list for the first time in his career. Harrison returned in late August and hit well the rest of the way, though the lingering effects of his injury sapped some of his power. It's safe to assume Harrison, now spending most of his time as Neil Walker's replacement at second base, will put together a more consistent 2016.

3B/SS Jung Ho Kang: This has nothing to do with performance, as Kang greatly exceeded expectations in his rookie season. Jumping straight from the Korean Baseball Organization to the Majors, Kang hit .287 with an .816 OPS, and proved solid defensively, as well. However, Kang's season came to an unfortunate end, as Chris Coghlan's takeout slide on Sept. 17 led to season-ending surgery on his left leg. When will Kang return? How will he bounce back from such serious injuries?
SS Jordy Mercer: Like Harrison, Mercer's 2015 was disrupted by a poor start and a trip to the disabled list. Mercer hit well in June but ended the year with a .244/.293/.320 batting line -- down from .255/.305/.387 in 2014. Mercer's defense at shortstop is more important to the Pirates than his hitting, but a return to his 2013-14 form at the plate would bolster the bottom of the batting order.

1B Michael Morse: Morse's rebound began the moment he left Marlins Park last year. Morse hit .231/.313/.336 with five homers and 19 RBIs in 2015, but those numbers were weighed down heavily by his time in Miami, as he hit .275 with a .782 OPS in 82 plate appearances for the Pirates. As Huntington has pointed out, Morse -- expected to be the right-handed half of the Pirates' first-base platoon -- isn't far removed from a 2014 season in which he hit .279/.336/.475 for the Giants.
LHP Jeff Locke: Locke's career has been marked by inconsistency, a trend he hopes to reverse this year. The 28-year-old lefty has been durable, making 30 starts in two of the past three seasons, but his All-Star campaign in 2013 best represented a troubling trend. Consider that Locke owns a career 3.00 first-half ERA and a 5.34 mark in the second half. He finished last year 8-11 with a 4.49 ERA in 168 1/3 innings. The Pirates are counting on Locke to be more consistent in 2016.
RHP Jameson Taillon: Taillon hasn't pitched in the Minors since 2013, as he spent all of 2014 recovering from Tommy John surgery and his return last year was delayed by a hernia. Now healthy, the highly touted prospect is confident his last two years weren't "lost," that his behind-the-scenes work eventually will lead him to the Majors. But how will he respond after so much time away? How quickly can he make the leap to the big leagues?