Michael Mariot and Justin Marks, the two most effective pitchers on the Class AA Northwest Arkansas staff, have been promoted to Class AAA Omaha.
Mariot, 23, the former Nebraska pitcher drafted in the eighth round in 2010, is 6-3 with a 3.40 ERA. Marks, is just 3-5, but has compiled a 3.80 ERA.
Omaha had one roster spot available because of the promotion of Vin Mazzaro to Kansas City. Another spot became available when Chris Dwyer (3-4, 6.97) was placed on the disabled list.
Dwyer had been projected to be the No. 5 starter in the PCL playoff rotation behind Jake Odorizzi, Ryan Verdugo, Doug Davis and Nate Adcock.
Mariot, from Southlake, Texas, ranks fifth in the Texas League both in ERA and with a WHIP ratio (walks plus hits divided by innings pitched) of 1.24. The right-hander opened the season in the Naturals’ bullpen but has a 3.13 ERA in 14 starts. In the second half of the season he has a 2.78 ERA in 68 innings.
Marks, 24, is a left-hander who was acquired along with Mazzaro from Oakland in the David DeJesus trade following the 2010 season. He was on the disabled list for nearly two months, but has made three starts and has compiled a 3.46 ERA with 13 strikeouts in 13 innings since his return.