Both manager Kirk Gibson and general manager Kevin Towers said it was still possible Ross could be ready for the April 1 opener, but that if there's any doubt the team will err on the side of caution.
• The D-backs spent time working on reading line drives during a baserunning drill Tuesday morning.
"A lot of it is concentration," Gibson said. "We put the time in and mentally think our way through it so we are better prepared to make better decisions on the bases."
Improving the team's baserunning has been an emphasis of camp this year.
Steve Gilbert is a reporter for MLB.com. Follow him on Twitter @SteveGilbertMLB. This story was not subject to the approval of Major League Baseball or its clubs.