Chelsea's world record transfer for Kepa Arrizabalaga could keep a door firmly open for Leeds United at the end of this season.
Blackman is the more experienced of the two and is expected to win the battle for the first team jersey.
If he can do enough to warrant Leeds wanting to sign him permanently at the end of the season, then the Whites have been helped out by Chelsea's £71 million investment.
Chelsea paid Marcelo Bielsa's former club Athletic Bilbao £71 million for Arrizabalaga, the most expensive fee ever for a goalkeeper.
Arrizabalaga, 23, is one year younger than Jamal Blackman and will go straight into the Chelsea first team.
The Blues have Willy Caballero and Rob Green backing up Arrizabalaga, neither long term options, but the fact Blackman isn't been given a chance even to compete, says a lot in itself.
He is playing for his future at Leeds, and if they decide they want him, luring Chelsea into a sale has probably become a bit easier.