Matchup: Justin Grimm vs. Felix Hernandez

The Rangers get a tough test in the opener of a four-game series in Seattle as they send Justin Grimm to the mound as a fill-in for Matt Harrison against Mariners ace Felix Hernandez. First pitch is set for 9:10 p.m. on FSSW and ESPN Dallas 103.3 FM.

Grimm (0-0, 0.00): Grimm will make his season debut in place of Harrison, who was scratched because of an inflamed nerve in his lower back. ... Grimm struggled in spring training while competing for the fifth spot in the Rangers' rotation, but he bounced back in his first regular-season start for Triple-A Round Rock last Friday, allowing one run in 5 2/3 innings. ... The 24-year-old right-hander was called up last year for an emergency start from Double-A Frisco and allowed three runs in six innings on June 16 against Houston. ... Grimm started nine days later against Detroit and allowed six runs in one inning. ... He was 9-3 with a 1.72 ERA at Frisco last year and finished the minor league season with Round Rock, going 2-3 with a 4.59 ERA. ... Grimm was recalled again last September and made two relief appearances.

Hernandez (1-1, 2.57): Hernandez, 27, is one of the premier pitchers in baseball and is looking for his 100th career win. ... He took the loss on Saturday against the Chicago White Sox, allowing four runs in six innings. ... Hernandez won his opening-day start, striking out eight while blanking the Oakland A's over 7 1/3 innings. ... Hernandez's issue has been run support; the Mariners have scored a major league low 3.5 runs per nine innings in his starts the over last three years. ... He has still managed 40 wins while posting a 2.92 ERA during that span. ... Hernandez has seen his average fastball velocity drop under 90 mph for the first time in his career. ... He is 12-16 with a 3.76 ERA lifetime against the Rangers and was 2-0 with an 0.53 ERA in two dominant starts against Texas last year.

Hitters: Elvis Andrus (15-for-61, 8 RBIs) and David Murphy (19-for-63, 2 HRs, 10 RBIs) are the only Rangers batting over .300 against King Felix with more than five career at-bats. Grimm has never faced the Mariners.