Mariners, Cardinals swap O'Neill, Gonzales

No. 29 overall prospect headed to St. Louis; lefty joins Seattle

Tyler O'Neill has hit 89 home runs over five seasons in the Minor Leagues. (Ben Sandstrom)

By Sam Dykstra / MiLB.com | July 21, 2017 11:58 PM

Straight-up prospect-for-prospect trades are rare, but the Mariners and Cardinals completed a deal Friday that accomplished just that.

The Cardinals acquired Mariners No. 2 prospect Tyler O'Neill while No. 18 St. Louis prospect Marco Gonzales will go the other way in the two-player swap.  

On its face, the deal is a perplexing one. O'Neill is ranked as the game's No. 29 overall prospect by MLB.com at the time of the trade while Gonzales had fallen down the Cardinals' rankings after being limited by shoulder and elbow injuries each of the previous two seasons.

However, those rankings only reflect preseason sentiments on both players. Their stocks have likely converged since the start of the 2017 season.

Coming off a 2016 campaign in which he hit .293 with an .882 OPS and 24 homers at Double-A Jackson, O'Neill struggled initially in his first taste of Triple-A ball with Tacoma, hitting just .236 with a .770 OPS and 14 homers in 84 games in the first half. He's also struck out in 27.3 percent of his plate appearances with the Rainiers, ninth-highest among the Pacific Coast League's 91 qualified hitters. He has caught fire recently, however, hitting five homers in his last five games with Tacoma including two in what would be his final game with a Mariners affiliate Thursday

"I'm finally on time with fastballs, getting good pitches to hit and not missing them like I was in the first few months of the season," he said after a two-homer game July 4. "Things are obviously turning around here."

Video: Tacoma's O'Neill mashes his second homer of game

"The one thing that we talk a lot about is finding those bats," Cardinals president of baseball operations John Mozeliak told MLB.com. "This is a player that has a lot of offensive upside. And at 22, he's accomplished a lot already in Triple-A. So for us, it adds to our offensive depth. [It's] not that we're not proud of our outfield depth, but we do think this offensive profile is unique. [He has] middle-of-the-order potential."

O'Neill will join a Triple-A Memphis squad that already features outfielder Harrison Bader, the Cardinals' No. 6 prospect. The Cardinals also have notable outfield depth in the Majors despite a recent injury to Stephen Piscotty. No. 8 prospect Magneuris Sierra was just optioned back to Double-A Springfield following the return of Randal Grichuk to the St. Louis lineup.

Gonzales is in his first season back from the Tommy John surgery he underwent in April 2016 and has shown flashes of being his old self this year with Memphis. The 25-year-old left-hander owned a 2.90 ERA and 1.04 WHIP with 57 strikeouts and 17 walks in 68 1/3 innings with the Redbirds. He made a spot start with the Cards on June 13 but floundered, giving up five earned runs on six hits over 3 1/3 innings in a loss to the Brewers.

Video: Marco Gonzales records a K for the Redbirds

A first-round pick out of Gonzaga in 2013, Gonzales had climbed quickly through the St. Louis system, making his Major League debut on June 25, 2014 before injuries set him back. When healthy, he has one of the Minors' best changeups to go with a more average fastball and curveball. The package can play up because of his solid command, as evidenced by his 6.3 percent walk rate in Memphis this season.

"Marco is a quality athlete with high character and a strong pitching pedigree who we feel fits our roster well in both the near and long term," Mariners general manager Jerry Dipoto said. "We find his current performance, preparedness and proximity to the Major Leagues to be very appealing traits in a pitcher, particularly a young lefty who is now under club control through the 2023 season."

Gonzales will take a spot on the Mariners' 40-man roster.

Sam Dykstra is a reporter for MiLB.com. Follow and interact with him on Twitter, @SamDykstraMiLB. This story was not subject to the approval of the National Association of Professional Baseball Leagues or its clubs.

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