Mark Warburton wants to bring in a defender to complete his Brentford squad.
The arrivals of Jota and Jon Toral took the number of signings up to nine following promotion from the Championship last season.
But boss Warburton is on the lookout for someone to provide additional cover as the final bit of business before September 1.
He said: "We may have one more coming in just to give us some more cover and competition for places.
"It's hard to get a place in our 18 now, which is what we want."
Meanwhile, midfielder Jake Reeves is among several Brentford youngsters available on loan.