Spiller was ruled out for the season after breaking his collarbone in his side's victory over the Minnesota Vikings, while Jackson also suffered an injury in the same game and could be out for several weeks.
Dixon, who joined the Bills in the off-season from the San Francisco 49ers, has admitted that he is looking to take his chance to prove his worth to Doug Marrone's side.
"It's time to step up and be great," Dixon told reporters. "It's what I've been waiting for, for a long time, getting that workhorse role and I just tried to take advantage."
Dixon has run for 137 yards off 27 carries this season, but has not scored a touchdown.