Jackie McNamara has a full squad to choose from in his first game as Dundee United manager.
United kept their squad intact on transfer deadline day despite reported interest in forward Johnny Russell.
Czech midfielder Rudi Skacel's short-term contract expired on Wednesday.
Rangers striker Francisco Sandaza is rated doubtful.
The Spaniard is struggling with a hamstring problem, while skipper Lee McCulloch has failed to recover from an ankle injury in time.
Lewis Macleod also misses the clash at Tannadice after being ruled out for seven weeks with knee ligament damage sustained against Montrose last weekend.
Williams is pushing for his first start when the Shrimps travel to York after two scoring cameos from the bench, including last weekend's dramatic late winner against Dagenham.
The midfielder has trained with Morecambe since the summer but clearance issues prevented him from signing professional terms until earlier this month.
"He's had a massive impact," Roche said. "He's been with us really since the start of pre-season and he's come in each day working his socks off knowing that he wasn't going to be able to get a deal until maybe January.
"So he's been coming in off his own back not getting paid and he's worked really, really hard.
"Given the chance when he's got it he's taken it and been absolutely brilliant. He's scored two very good goals but also Saturday's goal was so important to our season."
