Former Premier League striker Chris Sutton believes Brentford "will end up in a relegation battle" if they sell striker Ivan Toney during the January transfer window.
England international Toney will be free to return to action later this month once he has completed an eight-month suspension for breaching betting regulations, but he has been linked with a move away from Brentford.
Toney scored 32 goals in the Bees' first two seasons in the Premier League but they have struggled without him and a number of injured first-team players this term, with Thomas Frank's side currently four points above the relegation zone.
Sutton told BBC Radio 5 Live's Monday Night Club: "If Brentford want to stay in the Premier League, they have to keep Ivan Toney or do everything possible [to keep him]. They've had a phenomenal couple of seasons under Thomas Frank but they're scrapping at this moment in time.
"It's five on the spin that they've lost, that's a bit of a disaster for them. But they'll end up in a relegation battle if they get rid of Ivan Toney."