"You have to have depth," Maddon said. "A lot of times you think you do, and then it goes away fast, because of situations like this."
Aybar, who missed nearly two months with a strain of the same hamstring in 2008 -- paving the way for Longoria's Major League debut -- is mobile, but cannot push off the muscle or run at top speed. The Rays won't know for several days whether or not their utility infielder may be ready for Opening Day.
In the meantime, they will continue to monitor Blalock, a two-time All-Star who signed a Minor League deal with the team earlier this month. Though he has played exclusively at first base and designated hitter this spring, Blalock has been taking ground balls at third -- his primary position for the first six seasons of an eight-year career in Texas.
Blalock will start at third Saturday against the Pirates. Should Aybar miss significant time, both he or utility man Sean Rodriguez could man the position.
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"I should be OK over there," Blalock said. "I'm capable of filling in over there if they need me to."
Maddon also mentioned that outfielder Matt Joyce, who is nursing a right elbow strain, is "50-50" to be ready for Opening Day.
Yet there was also a bit of good news on Thursday. Catcher Dioner Navarro, who as recently as Tuesday was walking on crutches with a bruised nerve in his left leg, took indoor batting practice and participated in catching drills before Thursday's game. Navarro expects to take batting practice Saturday, play in a game Tuesday and be ready well in advance of Opening Day.
"That's the goal," Navarro said. "But it all depends how it feels. I'd like to be there before that."
"It's great that he's moving along, because he means a lot to us," Maddon said. "He should be fine by the opening of the season."
Navarro was wheeled off on a cart Saturday after a home-plate collision with Twins outfielder Jacque Jones.
"It was such a scary moment," Navarro said. "I really got scared. I thought it was going to be a while."