Bullard out for six to eight weeks
"On the negative front we are losing a very good player for six weeks but on the other side it could have been a lot longer," he told Sky Sports News after a scan showed no serious ligament damage.
"I am hopeful that Jimmy will be back on the field of play before the transfer window closes - that is what I am looking at and hopefully what everyone else is looking at."
The popular 31-year-old, who won the November league player of the month award after inspiring lowly Hull to a four-match unbeaten run, had only returned to action in October after missing nine months with an injury to his other knee.
The midfielder limped off in tears after just 19 minutes at Villa Park on Saturday.