AFC Wimbledon defender Jack Smith is expected to be out for about two months with a thigh injury.
Former Watford and Millwall left-back Smith, 31, had to go off during the second half of last Saturday's 2-1 home defeat against Cambridge United.
Scans have since shown that he suffered a grade two tear.
"It looks like Jack could be out for a couple of months, which is a big blow because he was in good form," manager Neal Ardley told the club website.
"It gives Callum Kennedy and Ben Harrison an opportunity to get back in and show what they are capable of, and hopefully during December they will do that.
"If they don't take their chances then we will have to look at what we do in January."