Lee will throw a side session on Tuesday, and "if that goes well, he would throw a simulated game on Friday," Wakamatsu said. "We're looking at March 10 being his first [Cactus League] start."
That would be against the Rangers in Surprise, Ariz.
Hernandez, who had a breakout season in 2009 with a 19-5 record and a 2.49 ERA, finishing second to Royals right-hander Zack Greinke for the American League Cy Young Award, will throw a simulated game on Thursday and probably make his Cactus League debut on March 9 against the Indians at Peoria Stadium.
Wakamatsu said he wanted to "slow both of them down a little bit."
The skipper wants to make sure Lee's left foot is completely healthy before putting the veteran lefty in a game situation and "the way we have it penciled out, we want to give these guys about 25 innings in Spring Training."
Though Wakamatsu has not announced his Opening Day starter against the Athletics in Oakland on April 5, it is expected to be Hernandez, with Lee pitching the second game of the four-game series.
Lee was scheduled to throw his second bullpen session of camp on Friday, but the Mariners pushed it back until Saturday.
Jim Street is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.