"He's flying here tonight. We'll evaluate him tomorrow," Girardi said. "Today he felt fine; we'll make sure he's OK. We'll have a heart-to-heart talk with him, how he feels about where he's at. Hopefully he can make a start in Seattle."
Tanaka, 26, has been on the disabled list since April 27 with tendinitis in his right wrist and a strained forearm. He threw 62 pitches in Wednesday's start, permitting three eared runs and four hits over three innings, and he reported no physical issues.
Girardi said that the Yankees' reports indicated that Tanaka's slider was good, and that he did not throw many splitters and made some mistakes with his fastball and split against Pawtucket. Girardi said that Tanaka could be expected to throw about 80 pitches against the Mariners.
"You want him to feel good, No. 1," Girardi said. "No. 2, you want him to feel comfortable with his stuff, that he feels that he's ready to go. You don't want someone going out there if they don't quite feel that they're ready to go. In a perfect world, he would start somewhere in Seattle."
In other injury updates, Girardi said that right-hander Chris Martin (right elbow tendinitis) threw in the bullpen on Wednesday and will join Triple-A Scranton/Wilkes-Barre on Saturday for a rehab game.
Right-hander Ivan Nova (Tommy John surgery) threw in an extended spring training game on Thursday in Tampa, Fla., and Girardi said that Nova will probably have one more extended spring outing before beginning a rehab assignment.
"Knock on wood, we're getting healthier," Girardi said. "We just have to keep the guys here healthy."
Bryan Hoch is a reporter for MLB.com. Follow him on Twitter @bryanhoch, on Facebook and read his MLBlog, Bombers Beat. This story was not subject to the approval of Major League Baseball or its clubs.