Martinez will start Thursday's game against the Astros, T.R. Sullivan of MLB.com reports.
Heading into the week, it appeared Cole Hamels would be in line to pick up the start for the series finale, but after the staff ace struggled in his last outing Aug. 26 against the Athletics, the Rangers elected to bump him back a day in the rotation, allowing Martinez to pick up the Thursday start. Martinez has submitted an unimpressive 5.26 ERA and 1.33 WHIP over 87.1 innings with the big club this season, but turned in one of his more impressive performances of the campaign while replacing Tyson Ross in the rotation last weekend. The right-hander covered seven innings against the Athletics in a losing effort, giving up three runs on four hits and two walks while tying his season high with seven strikeouts.