That would give the organization a better feel as to whether Morrow could make the switch.
Morrow was the organization's first-round Draft choice in 2006 out of the University of California-Berkeley, where he was used as a starter and reliever. He has such good stuff that making him a starter could go a long way in improving the Mariners' rotation next season.
"I, personally, don't want to do that in Spring Training," Riggleman said. "I don't even know if I'll be here in Spring Training, but if I am, I think it would be best to get those looks before Spring Training, which is a hard time to stretch people out for four or five innings."
Riggleman is working on a one-year contract, which was re-worked after he replaced John McLaren as manager on June 19, and there is no timetable as to when the organization will decide the fate of Riggleman and the current coaching staff.
Right-hander J.J. Putz is another factor in the Morrow decision.
One of the league's most reliable closers last season, when he saved 40 of his 42 save chances, Putz has been injured most of this season, and still hasn't returned to the dominant form he showed in 2007, evidenced again Tuesday night, when three of the four batters he faced in the bottom of the ninth inning got hits and Seattle lost a one-run lead and suffered an 11-10 loss.
"I talked to J.J. earlier today to see how he was feeling," Riggleman said. "He wasn't himself last night. He wasn't really throwing strikes as consistently as he needs to. He's struggling with it, and is irritated with himself."
Putz said he feels fine physically, although he's not at 100 percent, because of all the down time he had during two stints on the disabled list.
"He reached 96 [mph] last night, but he used to pitch at 96," Riggleman said. "I think he's still in Spring Training mode."
If the Mariners needed a closer in Wednesday night's game, Riggleman said he would go to Morrow, and then come back with Putz on Thursday and then, "run with it."
The Mariners figure to be better with Morrow in the rotation and Putz saving leads at the end of games, but both have to show they are capable of handling the roles.