The Hammers number two stopper has been in really impressive form since coming in for red-carded Adrian.
And he was at the centre of fierce speculation that the Irons would be forced to go in for Robert Green after showing uncertain pre-season form.
But in his column From the Boardroom at the www.whufc.com website Sullivan – after picking out Dimitri Payet and Victor Moses for special mention, added: “I also want to pay special tribute to goalkeeper Darren Randolph who has proved a lot of his critics wrong.
I think over the last three games he has shown he’s a very capable, international keeper who will be pressing Adrian all season for a first-team spot.”