Neither Saracens full-back Williams and Cardiff flanker Navidi have featured in Wales' first three games of this year's tournament as they both underwent rehabilitation for ankle and hamstring injuries respectively.
Williams has been on the sidelines since damaging his ankle in the World Cup semi-final defeat to South Africa last October, while Navidi pulled his hamstring in training ahead of the Six Nations opener against Italy.
Attack coach Jones says both men have made steady progress in their recoveries and could be included in Wayne Pivac's squad for the trip to Twickenham on March 7.
"The situation with Liam and Josh is that they're in our environment," said Jones. "They're working hard, getting in the reps and load that's needed to make them available for selection.
"Hopefully they can tick every box along the way and they can put their hand up for selection."
On Williams, Jones added: "The key is how his training week goes this week and next. Things like how we manage his load and get him up to speed."
The return to fitness of Williams and Navidi couldn't come at a better time with Wales left counting the cost of their loss to France last weekend.
Wing Josh Adams will miss the rest of the Six Nations after undergoing ankle surgery, while George North will need to pass concussion protocol after a blow to he head in the 27-23 defeat to Les Bleus.