Jose Mourinho says Tottenham's defensive calamities have left him feeling sorry for his attacking players.

Spurs' surge up the table has been severely undermined by some horror shows at the back – no Premier League side have conceded more goals in all competitions since Mourinho arrived at the north London club in November.

There is no problem at the other end as the likes of Harry Kane, Dele Alli and Son Heung-min have been firing, but Mourinho's team would comfortably be sitting in the top four if they had defended properly.

And the Portuguese knows the attacking stars are within their rights to wonder what is going on behind them.

"The problem is the way we concede the goals and the way we play," he said ahead of a New Year's Day trip to Southampton.

"But we have to improve. We concede too many goals and it is very frustrating.

"If I was one of my attacking players I would be very frustrated that behind we are not able to stop it."

Despite their defensive fragility, Mourinho again reiterated that the way to cure it will be found on the training ground, not in the transfer market, with the window reopening on Wednesday.

"January we have a little bit more time to work and with work we are going to try to improve," he added.

Spurs have at least improved their away form under the former Chelsea and Manchester United boss, having not won on the road since January prior to his arrival.

They will face another stern test at St Mary's on Wednesday, but Mourinho is encouraged by his side's fighting spirit as they came from behind to earn points in the last two games.

"Four matches away, we won two, we drew one and we lost one," he said. "Is that better than before? Yes. Is it perfect? No.

"So it is frustrating, but it is also a great feeling to know that the team never gives up, it is also a great feeling to know that even in the most difficult circumstances we go and we go and we go.

"I want to praise that fantastic spirit."

Spurs will be without Danny Rose, who could be out for another fortnight with a muscle injury, though Moussa Sissoko and Harry Winks are back in contention after suspension.

Asked how long Rose will be out for, Mourinho replied: "I don't know. I would guess, but maybe I am wrong, a couple of weeks.

"But honestly I cannot tell you. We have Winks and Sissoko back from suspension and I don't think we are going to have anyone back from injuries."