The Seattle Mariners acquired right-handed reliever Trent Thornton in a trade with the Toronto Blue Jays on Wednesday, adding to their bullpen depth as they prepare to potentially deal away major league players before the Aug. 1 trade deadline.

Thornton, 29, was designated for assignment last week by the Blue Jays after the nabbed left-handed reliever Genesis Cabrera in a deal with St. Louis. For Thornton, Toronto will receive infielder Mason McCoy. Both players will report to Triple-A.

In four games with the Blue Jays this season, Thornton posted a 1.69 ERA, struck out five and walked one. His heavy-spinning curveball is seen as the best in a four-pitch arsenal, and the Mariners' ability to take retread relievers and turn them into productive bullpen arms has been a vital part of their ascent in recent years.

Over five seasons, Thornton has a 4.77 ERA in 260.1 innings and has struck out 249 while walking 98. Depending on how much time Thornton spends in the major leagues this season, the Mariners will have either two or three years of control before he reaches free agency.

Seattle, currently in fourth place in the American League West, is 4½ games back of the Blue Jays for the final wild card spot. If they fall further, the Mariners could trade closer Paul Sewald and outfielder Teoscar Hernández, both of whom would be coveted in a market that currently has few top-end players.

McCoy, 28, can play third base, shortstop and second base and is hitting .234/.330/.407 with 11 home runs at Triple-A. He was dealt from Baltimore to Seattle last year.