Crystal Palace manager Alan Pardew has claimed that Patrick Bamford must "harden as a professional" if he is to progress in his career.
Chelsea striker Bamford recently ended his season-long loan at Palace after failing to make a single Premier League start for the Eagles.
The 22-year-old then initially branded his time at Palace "terrible", before back-tracking and issuing an apology.
"Being lightweight is not a criticism I've heard or noticed in his game. He's just not hardened yet," PA quotes Pardew as saying. "He needs to harden as a professional. This experience will harden him. He's trained well and tried to get into the team. That's hardening your mentality.
"At Middlesbrough [last season] he was playing every week and training every week, it's all good and flows nicely.
"But it hasn't flowed here, it's a different experience. You've got to fight and this will harden him up."
Bamford wants to move to another Premier League club on loan, although a return to Boro could also be on the cards given that they are flying high at the top of the Championship.