Both players have been linked with moves away from the Santiago Bernabeu, although with the La Liga season starting this weekend, they each remain on Madrid's books.
Following the team's friendly showdown with Roma on Sunday, Zidane was asked about the pair. The Frenchman said he feels he can "count on" both, but he refused to guarantee Bale and James would still be at the club by the time the transfer window closes, per Ryan Benson of Goal:
"James and Bale are players of the squad. They are both registered, but anything can happen and I, as a coach of Real Madrid, must count on them.
"I count on them 100 per cent. James has not been summoned [to the squad recently], but this can change. Even before the end of the transfer window, everything can happen."
James has yet to feature in any of Madrid's pre-season games. Bale returned to the squad for Sunday's 2-2 draw with Roma following a three-game absence and was brought on as a late substitute.
Zidane was also asked about the possibility of more players coming into the squad before the window closes on September 2, with Paris Saint-Germain forward Neymar and Manchester United midfielder Paul Pogba linked.
"We are with what we have, and we only think about that," he said. "Our mind is only thinking about Saturday [their next match]."
Dermot Corrigan of ESPN FC offered his analysis of Zidane's comments:
Madrid will begin their La Liga season against Celta Vigo in what has the potential to be an intriguing game.
Lucas Navarrete of Managing Madrid commented on the team's below-par outings in pre-season:
With Madrid struggling in their preparations, it will be fascinating to see who Zidane turns to for the first competitive game of the campaign.
While he may consider Bale and James dependable players, it would be a shock to see either involved on Saturday. The latter will be a long way short of fitness after no minutes in pre-season, whereas Bale came close to being sold in the window, with a transfer to Jiangsu Suning collapsing.
Despite spending huge money in the window already, speculation about possible incomings in the final days of the transfer window appears set to intensify, too.
Pogba or Neymar would represent spectacular acquisitions for the club, although deals of such magnitude will be difficult to get done. Ajax midfielder Donny van de Beek appears to be a more likely arrival at this juncture after Marca's Juan Ignacio Garia-Ochoa reported the Dutchman has agreed terms with Madrid.