In nine games for the Tigers, Williams scored 10 tries but he has spent the last three years with Aviva Premiership rugby union outfit Newcastle Falcons where he has scored 12 tries in 46 appearances.
He also made two appearances for England during his first stint in the 13-a-side code.
“It’s been really good,” said Williams after the first day of his trial at Craven Park on Tuesday.
“The boys got a good win at the weekend so there’s a really positive environment around and everyone’s really happy and cheerful so they’ve made me very welcome.
“I’m thankful for the chance to come here. It’s a great club and I’m thankful to get the chance to come and play with the boys and see where I can go from there.”
“We’ve given him the opportunity to train, have a look at our facilities and we’ll go from there,” said Rovers Head Coach Justin Morgan.
“He might get a run-out in the Nines next Tuesday to see how he goes but we’ll just be putting him through a series of tests to see where he’s at compared to our players and see if he fits into our environment.
“If he does then we’ll take the next step with him and his agent.”