"This will be a big outing for him," A's manager Bob Melvin said. "Puts him on his way. Real game type of situation. Once you get up to that 60-, 65-pitch mark, it means you're real close, hopefully, to getting him back here."
The A's would like to see Gray build up to close to 90 pitches, meaning he could potentially need to throw in only one more Minor League game before rejoining the A's. Based on his schedule, the earliest he could return is May 2.
"Potentially, if everything goes well," Melvin said. "You hate to get ahead of yourself because something could transpire in the meantime that's not necessarily a setback. You might just think you need one more time out. That's kind of the the plan as of right now."
Gray was pleased with his velocity Monday and said he was consistently throwing each of his four pitches for strikes.
"I felt great," he said. "Everything was coming out really well. It was a really good step."
Gray was limited to 22 starts last year, pitching to a career-worst 5.69 ERA when not sidelined by two separate injuries. The right-hander was in line for another Opening Day start this year before sustaining the lat strain. The nod was awarded to Kendall Graveman, who is also on the 10-day disabled list with a shoulder strain. Graveman said Tuesday he expects to throw a bullpen session Friday and remains hopeful of only missing one start.
• Right-hander Chris Bassitt (Tommy John surgery) will throw two 15-pitch simulated innings in extended spring training on Wednesday.
• Infielder Joey Wendle, who has been on the disabled list with a right shoulder strain, is scheduled to fly to Nashville on Wednesday to begin a rehab stint with the Sounds. He'll start at DH.
Jane Lee has covered the A's for MLB.com since 2010. This story was not subject to the approval of Major League Baseball or its clubs.