Mariners outfielder Ben Gamel has been diagnosed with a strained right oblique muscle and is expected to be sidelined anywhere from four to six weeks, the team told reporters on Monday (Twitter link via’s Greg Johns). That almost certainly means he’ll open the season on the disabled list, and if the recovery takes closer to the six-week end of the spectrum, he could miss the first two to three weeks of the season. Gamel, 25, is in line for regular at-bats with the 2018 Mariners after posting a solid .275/.322/.413 slash with 11 homers, 27 doubles and five triples through 550 plate appearances last year in his first full big league season. Gamel turned in an exceptional first half in 2017, slashing .323/.379/.449 before cratering with a .227/.262/.376 slash following the All-Star break. He joins first baseman Ryon Healy on the list of notable Mariners injuries in Spring Training, though Healy, unlike Gamel, could potentially be ready for Opening Day.