Overall, Kivlehan owns a .333/.373/.556 batting line with 21 hits (10 extra-base hits) and 11 RBIs in 15 games for Leones.
Kivlehan raced through the Mariners' system after being selected in the fourth round of the 2012 Draft, spending the entire 2015 season at Triple-A Tacoma. The Rutgers product enjoyed a slight uptick in power playing in the Pacific Coast League, hitting a career-high 22 home runs in 123 games, though it came at the cost of a career-worst .256 average.
Kivlehan did improve his defensive versatility, seeing time at all three outfield spots to go along with his usual reps at first and third base, which likely made him an appealing trade candidate to the Rangers.
Here's a look at some of the other top prospects currently making waves in the offseason winter leagues.
• Alex Balog, RHP, Rockies -- Balog, the club's No. 24 prospect, missed the first three months of the 2015 season with a groin strain but finished strong, posting a 3.71 ERA in 97 innings for Class A Advanced Modesto. The 23-year-old right-hander is making up for the lost this offseason in the Australian Baseball League, where he's 5-2 (in eight starts) with a 1.35 ERA (second best in ABL) and 45 strikeouts in 46 2/3 innings for the Sydney Blue Sox.
• Rhys Hoskins, 1B, Phillies -- A fifth-round Draft pick in 2014 out of Cal State-Sacramento, Hoskins opened eyes during his full-season debut by hitting .319/.395/.518 in 135 games between Class A Lakewood and Class A Advanced Clearwater. The 22-year-old first baseman also paced the organization with 17 home runs, 36 doubles and 258 total bases. Hoskins' bat has been on display this offseason in the Australian Baseball League, where he has a .922 OPS, five home runs, 14 doubles and 27 RBIs in 31 games for the Sydney Blue Sox. He's also driven in at least one run in each of his last six games, hitting .417 with one home run, two doubles and 13 RBIs in that span.
• Adalberto Mejia, LHP, Giants -- The Giants' No. 12 prospect began the season on the restricted list after testing positive for a performing-enhancing substance, but he pitched well at Double-A Richmond upon his return in early June, showing command of four offerings along with his usual feel for changing speeds. The 22-year-old southpaw was added to San Francisco's 40-man roster following a successful stint in the Arizona Fall League (3.48 ERA in 31 innings), and he's now tacking on more innings in the Dominican Republic, where he has a 1.42 ERA and 10 strikeouts across three starts for Gigantes del Cibao.
• Joey Rickard, OF, Orioles -- Originally a ninth-round Draft pick of the Rays in 2012, Rickard was selected by the Orioles in last week's Rule 5 Draft. Though the 24-year-old stands out for his ability to play all three outfield spots, he's coming off a career-best campaign in which he hit .321/.427/.447 with 28 doubles, eight triples and 23 stolen bases in 117 games between Class A Advanced Charlotte, Double-A Montgomery and Triple-A Durham.
• Dylan Cozens, OF, Phillies -- A second-round Draft pick in 2012, Cozens' prospect stock took a hit with an underwhelming 2014 full-season debut in the South Atlantic League. However, he got back on track last season in the Florida State League (.746 OPS in 96 games), ultimately finishing with a successful 11-game stint with Double-A Reading. The 6-foot-6, 235-pound outfielder is strengthening his case to re-enter the Phillies' Top 30 with a strong showing in the Puerto Rican Winter League, where he's hitting .346/.370/.558 through 15 games for Indios de Mayaguez.
• Orlando Arcia, SS, Brewers -- The Brewers' No. 1 prospect (No. 12 overall) excelled last offseason playing for Caribes de Anzoategui, setting the stage for a breakthrough 2015 campaign in which he batted .307/.347/.453 with eight home runs, 37 doubles, eight triples and 25 stolen bases for Double-A Biloxi. It's been more of the same this offseason for the 21-year-old shortstop, who's hitting .308 with a .794 OPS and 24 hits through 21 games for Caribes.
• Wuilmer Becerra, OF, Mets -- Back in 2012, Becerra was viewed as a "throw-in" as part of the R.A. Dickey trade that netted the Mets Noah Syndergaard and Travis d'Arnaud. Now, he ranks as the organization's No. 12 prospect after hitting .290/.342/.423 with nine home runs, 27 doubles and 16 stolen bases in 118 games for Class A Savannah in his full-season debut. The 21-year-old outfielder -- who has the potential for average-or-better tools across the board -- hasn't skipped a beat this offseason in Venezuela, hitting .370 through his first nine games for Tigres de Aragua.