De Jong came through a Under-21 Premier League game to put himself in the frame for a first-team comeback against Stoke City on Sunday.
The 25-year-old played 69 minutes of the 1-1 draw against West Bromwich Albion at the club’s training ground.
Peter Beardsley: “Siem’s a top footballer.
“I watch him play, and I have to say – and it probably sounds big-headed – he’s a lot like I was.
“He does a lot of unseen work in putting people under pressure and closing them down.
“He has such a football brain – he’s a proper No10. I’ve been very impressed – he’s a class act.
“I absolutely love him. I’ve been to watch him a couple of times at Ajax as a scout, if you like. He’s got a brilliant brain and can understand the game and slow it down and quicken it up.”