The offseason goal for the Mariners was never just to build an effective five-man rotation for their big-league club — although club officials believe they did that, too, in trades that returned Drew Smyly and Yovani Gallardo.
General manager Jerry Dipoto instead talked repeatedly of building an upper-level stable of 12 to 15 starting pitchers both as a hedge against inevitable injuries and as a bridge to the future.
Last week’s deal to obtain right-hander Chase De Jong was another step in that process. He is 23 with three options remaining and, barring a string of injuries to the projected rotation, has no chance to open the season in the big leagues.