"Jessica Jones" star teases possible return to MCU in "Daredevil: Born Again."
Ritter wears "Daredevil" t-shirt in gym photos, sparking rumors of return.
Reports indicate Punisher may replace Ritter's Jones due to schedule conflicts.
Fans speculate on potential returns of Luke Cage, Iron Fist, and others in "Born Again."
Ritter finished filming "Orphan Black: Echoes" in December with no publicly known projects scheduled.
"Born Again" filming is to begin in February.
Ritter's return as Jones in MCU remains unconfirmed.