Biggar suffered a knee injury while playing for Northampton last Saturday while Williams and Navidi have faced prolonged spells on the sidelines. North is also set to be available after suffering concussion against France two weeks ago.
And Wales technical advisor Warburton insists there are grounds for optimism on the fitness front ahead of the trip to Twickenham.
“He’s looking good,” said Warburton when asked about the fitness of Biggar.
“The initial signs are positive. He doesn’t need a scan. It puts our team selection on hold for a while because we have to wait to see how he turns up tomorrow.
“He’s going to train and do stuff with the physios. But everyday so far, the feedback from the physios has been good, he’s had a really good response to the stages of physio.
“He’s ticking all the boxes he needs to. He’s on a good course so, hopefully, with no hiccups, we’ll have some good news.
“I would say, at this stage, we’re confident but there are no guarantees. There’s a hurdle every day, the training becomes gradually more intense and will climax towards the end of the week.
“So if he can pass that, then all good. We’re taking it day by day but the first two days have been all good.
“Josh is back in full training and is available again. We do a pretty demanding drill with Byron and he turned up and absolutely nailed it.
“I saw it and just thought: ‘He’s ready’. From a coaching and back row perspective, that physicality, that dynamism, ball-carrying ability, work on the floor.
“He’s been a big player for us in the past few years. Liam’s back in full training. If you ask him, he was ready to play against France.
“He’s back in full training. He will hopefully be in contention to start.
“This is the sort of cauldron he would love to be thrown into.”
As Wales captain Warburton won twice at Twickenham in 2012 and at the 2015 Rugby World Cup. And he insists his players are relishing the opportunity of facing a strong England side this weekend.
He said: “We go to England now and we’re not as down as you’d think. We can probably pick out one or two moments from each game which have been critical.
“Rather than the personal rivalries, the players get more energised over the history of the game and the occasion. That does mean a lot to the players.
“To represent Wales at Twickenham and get a win down there is massive and you know how much it means to the country. It’s a much easier trip to the Co-Op to get your milk because everyone is so happy.
“As players we all know each other and follow each other on Instagram so the personal rivalry has gone, but the national rivalry is still there.”
