"It just hasn't gotten better," manager Terry Collins said. "Maybe it was worse than we thought in the beginning."
Tejada will attempt to ramp up his running program Wednesday, though that comes with no guarantees; he has already sustained multiple setbacks during his five-week rehab.
Tejada's backup, Ronny Cedeno, ran on the infield dirt Tuesday in his own rehab from a strained left calf, but he has yet to appear in a Minor League game. And third-string shortstop Justin Turner played in an extended spring training game, but he did not test his sprained right ankle on the bases.
With those three shortstops all on the DL, the Mets have been proceeding on a nightly basis with fourth-stringer Omar Quintanilla.
"We've missed him a lot," Collins said of Tejada in particular. "Omar's come up and he's done a good job. Ronny did a good job. We've caught the ball. But Ruben is an offensive force, and right now it's obvious we're missing that."