Chile international defender Jara is still awaiting a visa following his recent switch from South America but, having also been forced out of Saturday's 3-1 victory over Plymouth, is expected to arrive in the country by the middle of the week.
Moore also missed out at the weekend after he failed to recover from an ankle injury and remains a doubt for Saturday's trip to Middlesbrough.
Head coach Roberto Di Matteo has reported no fresh injuries from the victory over the Pilgrims but, at the same time, none of his long-term absentees are expected to make it.
James Morrison (heel), Neil Clement and Ishmael Miller (both knee) all remain sidelined.
