The 24-year-old is part of the Red Rose squad for the Calcutta Cup clash after making his long-awaited return to action for club side Saracens last weekend.
A whiteboard on display at England's training camp on Tuesday appeared to outline boss Eddie Jones's starting XV, with Vunipola among those to feature from the off, but Borthwick was unwilling to be drawn into any rumours regarding his side's plans for the visit of Scotland.
"[Vunipola] trained well yesterday, and I think having Billy and Nathan Hughes as No 8s are both powerful ball carriers, it's good for us," he told reporters.
"We've got competition for places throughout the team. We've got options, we've got flexibility, as ever with international rugby it's a 23-man effort, you constantly need all the players for 80 minutes at the top of their game and that's what we are preparing for.
"Whatever the starting team is, whoever our finishers are, and our finishers have always done a fantastic job, we know international rugby is 80 minutes and it takes 23 players to win the game. So we prepare every player as thoroughly as we can to make sure the squad is in the best shape possible come matchday."
Prior to his comeback in Saracens' victory over Newcastle Falcons last Sunday, Vunipola had missed three months of action since being stretchered off with a knee problem in England's meeting with Argentina.