Sunderland recall Jeremain Lens but he could be sold in January

Sunderland boss Sam Allardyce has challenged midfielder Jeremain Lens to prove his class after welcoming him back in from the cold.

The Netherlands international, who joined the Black Cats from Dynamo Kiev this summer for an initial £8 million, this week hinted that he might look for a move away from the Stadium of Light after failing to force his way into Allardyce's plans.

His comments came as he waited to be punished for a disciplinary incident after the 1-0 home defeat by Watford on Dec. 12.

That process is now complete and Lens has been added to the squad for the Boxing Day trip to Manchester City with Allardyce having left him in little doubt as to what is required of him.

The manager said: "Get on the pitch and show us what you can do and prove to us all that you're the talent we expected with the performances that have been achieved in other parts of the world before, which obviously was why [predecessor] Dick [Advocaat] brought him here.

"I'd like to see some of that, and hopefully that can be the case, him pushing on from now on."

Asked if Lens has a future on Wearside if he can do that, Allardyce replied: "Absolutely because he is one of our biggest signings.

"We have been through our process to get it right, we are both of the same opinion in terms of how we go forward. I have put him back in the squad and when he gets the chance to play, let's hope he can grasp that chance and prove that he's an immense talent, as has been shown in other countries."

Lens' suggestion that he could move in January was met with a smile by Allardyce, who is now heavily engaged in the club's recruitment activity after confirming sporting director Lee Congerton, who is reported to have been working a period of notice for some time, is now on "gardening leave."

He said: "Well, we will wait and see, then. If he comes to me and tells me which club is going to buy him, then we will probably look at it and maybe come to a mutual agreement.

"If him and his agent want to find a football club and say, 'Here we are, we want to go here and here is this amount of money' or more than we paid for him, then I may well say yes."

Allardyce is hoping to make "at least two acquisitions," "as early as possible" in the winter window after revealing that central defender Younes Kaboul and full-back Adam Matthews could be missing for some time with hamstring and ankle ligament injuries respectively.

Meanwhile, the Black Cats boss reacted angrily to the decision to move his side's league trip to Swansea back by 24 hours to Wednesday, Jan. 13 in between games at Arsenal and Tottenham, all inside seven days.

He said: "It's hugely disappointing, but I'll cover that when we get nearer the game. I will produce the evidence on why [Premier League chairman] Richard Scudamore and the board were totally wrong in this decision, and I mean totally wrong."