JEREMAIN LENS’ Sunderland future is in considerable doubt after he was axed from Saturday’s match-day squad at Chelsea because of a “disciplinary” matter.

While his Black Cats team-mates were crashing to a 3-1 defeat at Stamford Bridge, Lens was on Wearside after spending most of last week training with Sunderland’s under-21 squad.

Allardyce confirmed Lens’ demotion was due to a “disciplinary decision”, but refused to elaborate on the Dutchman’s indiscretions.

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However, it is understood that the Sunderland boss has become frustrated with Lens’ attitude on the training ground, and his reaction to starting just one Premier League game since Allardyce was appointed in the middle of October.

Having been suspended for Allardyce’s opening game at West Brom, Lens started the 3-0 win over Newcastle United, but did not finish the match as he was replaced by Seb Larsson.

He has only made three brief substitute appearances since, with Allardyce questioning both his work rate and his willingness to adhere to team instructions.

It is now anticipated that Sunderland will listen to offers for him in next month’s transfer window, although Allardyce’s desire to raise funds for his own spending will have to be balanced against Ellis Short’s understandable reluctance to suffer a major loss on a player who arrived in a £13m move from Dynamo Kiev just five months ago.

Lens’ reaction to his latest snub will be instructive, as Allardyce will not want to retain him if there is a chance of him becoming a disruptive influence because of his role on the periphery of first-team affairs.

In that scenario, Allardyce, who has effectively taken over control of transfer matters from departing sporting director Lee Congerton, would push for Lens to leave on loan in the second half of the season.

The 28-year-old Dutchman signed a four-year contract when he moved to Wearside in the summer, with former boss Dick Advocaat having pushed extremely hard to secure his signature.

Advocaat’s departure has deprived him of his biggest supporter though, and it is becoming increasingly difficult to see how he can be accommodated in Allardyce’s preferred system.

Tellingly, the Sunderland boss has promoted Duncan Watmore above Lens in the pecking order, largely as a result of the England Under-21 international’s work rate, commitment and eagerness to improve.

Watmore was involved in Saturday’s defeat to Chelsea, a result that leaves the Black Cats five points adrift of the safety zone ahead of a daunting Christmas double-header that pits them against Manchester City and Liverpool.

With Newcastle, Norwich and Bournemouth all picking up at least a point at the weekend – not to mention Chelsea, who comfortably claimed all three – Sunderland’s position is becoming increasingly perilous.

“The gap is a massive concern,” conceded Allardyce, after Fabio Borini’s second-half consolation failed to cancel out earlier goals from Branislav Ivanovic, Pedro and Oscar. “If we’d got a result against Watford (when Sunderland lost 1-0), it would have taken us a little closer to the points-per-games total (target).

“If we’d beaten Watford, we’d have been on 15 points after 16 games, and I’d have accumulated 12 points in my first eight games, which would have been mega.

“We failed that miserably though, and that for me was the bigger disappointment than this one. I’m disappointed with this performance, but we didn’t deserve anything.

“But not beating Watford was the real big one, especially with knowing what fixtures we’ve got coming over the Christmas period.”

Sunderland were unfortunate to run into a Chelsea side clearly determined to prove a point following last week’s departure of Jose Mourinho.

On a strange afternoon at Stamford Bridge, Chelsea’s fans booed Cesc Fabregas and Diego Costa when their names were read out before kick-off, and unfurled a number of banners, one of which described Fabregas, Costa and Eden Hazard as “rats”.

With new boss Guus Hiddink watching on from the stands, Chelsea’s players delivered a much-improved performance that seemed to support Mourinho’s assertion that they “betrayed” him, although Allardyce pointed out that Sunderland’s deficiencies made it easy for the home side to catch the eye.

“We gave Chelsea the opportunity to be very good,” he said. “They took full advantage of that, which you’d expect with the squad of players they have.

“We encouraged them so much, and it was mind-boggling for me to see my players play with what looked like so much fear and worry about the opposition.

“They could hardly put one foot in front of the other. We got better when we changed the system and put the subs on, but by that time it was too late.

“Chelsea thoroughly deserved to win, and it’s obviously a big result for them and a very poor result for us.”