Amateur Career
Marks was 21-8 with 287 strikeouts in high school. He was originally drafted by the Boston Red Sox in the 37th round of the 2006 amateur draft, one pick after Ronnie Welty, but did not sign a contract, opting for college. As a freshman, he was 9-2 with a 2.67 ERA. He had the lowest opponent average (.189) in the Big East Conference, tied for third in wins and tied Danny Otero for 5th in strikeouts (87). He was named Big East Freshman of the Year. Louisville made it to the 2007 College World Series. As a sophomore for Louisville, he was even better (9-2, 2.37). He tied Dan Osterbrock and George Brown for the Big East win lead, was second to Matt Tosoni in ERA and his 89 whiffs were second, one behind Scott Barnes. He joined Barnes, Brown and Corey Young as the All-Conference pitchers, with Brown beating him out for Pitcher of the Year.
His junior year, he was 11-3 with 129 K in 105 IP though his ERA rose to 3.77. He led the Big East in both wins and Ks (30 ahead of runner-up Jarryd Summers). He won Big East Pitcher of the Year (Randy Fontanez, Summers and Keith Cardwell were the other All-Conference pitchers) and Collegiate Baseball named him a second-team All-American (behind Stephen Strasburg, Mike Leake, A.J. Morris, Louis Coleman, Deck McGuire, Daniel Bubona and Addison Reed). He broke Brian Bentley’s school records for career strikeouts (305 to 243) and wins (29 to 22) and Scott Reburn’s career ERA mark (2.96 to 3.11). He tied for 10th in NCAA Division I in wins, was 14th in strikeout ratio and was 9th in whiffs (between Kyle Gibson and Josh Spence.
Oakland A’s
He did ink a contract when the Oakland Athletics took him in the 3rd round of the 2009 amateur draft, between Wil Myers and Robbie Erlin, signing for a bonus of $375,300. He was the 92nd overall pick. The scout was Matt Ranson. Marks was just awful in his only start for the 2009 AZL A’s; he faced 7 batters and allowed three hits (one homer), four walks and six runs. He had a rough 2010 as well with the Kane County Cougars (3-10, 4.92) and Stockton Ports (3-1, 4.58). He did strike out 136 in 129 1/3 IP and wasn’t allowing a slew of hits (.258 opponent average) or walks (49). He tied Keaton Hayenga for third in the Midwest League in losses. Among A’s farmhands, he tied Anthony Capra and Anvioris Ramirez for the most losses, was 4th in strikeouts (behind Shawn Haviland, Dan Straily and Ben Hornbeck) and tied for 4th with 10 hit batsmen.
Kansas City Royals
He traded with Vin Mazzaro to the Kansas City Royals for David DeJesus on November 10 of that year. In his first season in the Royals system, 2011, he had 140 strikeouts in 144 2/3 innings, with only 49 walks allowed for the Wilmington Blue Rocks (going 8-8, 3.98). He led the Carolina League in Ks, 13 ahead of Barret Loux, and was second in the Royals chain (13 behind Jake Odorizzi). 2012 was not as good; he split time between the AZL Royals (1 R in 5 IP), Northwest Arkansas Naturals (3-5, 3.80) and Omaha Storm Chasers (0-1, 9 R in 1 2/3 IP) for a composite 4-6, 4.50 record with 44 walks and 81 K in 92 IP. He turned it back around in the fall, going 5-1 with a 2.59 ERA for the Surprise Saguaros. He led the Arizona Fall League in wins; no one else had more than 3 and his 22 strikeouts tied for 9th.
Justin split 2013 between the Naturals (2-0, 1.59 in 2 G) and Omaha (6-13, 4.58 in 24 G). He struck out 129 in 141 innings but walked 66. He lost game 3 of the 2013 PCL championship series. He tied Matt Shoemaker for third in the PCL in losses, tied Nick Additon for 9th in strikeouts (117) and was 4th in walks (61, behind Johnny Hellweg, Maikel Cleto and Chris Dwyer). Among Royals minor leaguers, he tied for 6th in wins, was third in losses (one behind Sugar Ray Marimon and John Lamb), was 4th in walks (behind Sam Selman, Cleto and Dwyer) and was 5th in strikeouts (between Christian Binford and Selman).
He began 2014 back with Omaha (1-1, 3.24 in 3 G) but was soon called up by the Royals when Lorenzo Cain went on the disabled list. He made his big league debut on April 20th, replacing Louis Coleman in the top of the 6th with a 5-1 deficit against the Minnesota Twins. He got to full counts on his first two batters, retiring Aaron Hicks on a fly and walking Eduardo Escobar. He struck out the next batters, Brian Dozier and Joe Mauer. He struggled in the 7th, though. Trevor Plouffe doubled, Chris Colabello popped out but Jason Kubel singled in one run, Josmil Pinto drew a walk and Kurt Suzuki smacked a two-run double. Marks walked Hicks, retired Escobar, allowed a Dozier single to load the bags then got Mauer on a liner. Michael Mariot relieved him in the 8th.