You were expecting Fraley, weren’t you? Picking Fraley would have been the easy way out. If Fraley comes up later this year and performs well, then yes, he will be in the Opening Day outfield for the Mariners.
But the Mariners might also want to control his service time and have him open the season next year in Tacoma where he would be reunited with his former Arkansas Travelers teammates that will also be in Tacoma next year.
That opens the door for Bishop to crack the opening day lineup in center field. If Bishop hadn’t suffered his own unfortunate injury then he’d be the everyday center fielder right now. The Mariners need to figure out what they have in Bishop. Is he an everyday outfielder, or better suited as a fourth outfielder on a good team?
Having him start the season as the everyday center fielder would allow Fraley a little more seasoning on the farm, and allow the team to manipulate his service time if needed (even though no team will ever claim they are doing that).