"He is struggling and is probably 60/40 against to be fit for Saturday," Boro No2 Malcolm Crosby told the Evening Gazette ahead of the game with Derby. "He's doubtful, but I'm sure if he doesn't make Saturday then he will make the next game."
Crosby added: "I think the pace of the game and maybe the power in the Premier League players will take some time to get accustomed to.
"I think in Holland the game is played at a bit of a slower pace and I don't think it's as aggressive so we have to give the lad time.
"Afonso's come into the team at a difficult time.
"If he'd come into the team and we were winning every game and were near the top of the league then I think it would be a little different, but he's come into a team that's struggling against relegation if you like. It will take him time and we have to give him a chance and I'm sure the fans will."