Tottenham's Mousa Dembele has the ability to play for Real Madrid but he is not fulfilling his potential - Les Ferdinand

Mousa Dembele is failing to fulfil his potential at Tottenham and is good enough to play for Real Madrid, according to former coach Les Ferdinand.

Dembele has struggled to establish himself this season under Mauricio Pochettino and has rarely been first choice in midfield for Premier League fixtures.

It is a far cry from Dembele’s early months at the club. The Belgian quickly became a key man for Andre Villas-Boas after joining from Fulham for £15million in the summer of 2012.

It was a similar story with Tim Sherwood in charge but Dembele has fallen away under Pochettino – something that frustrates Ferdinand, who now works for Queens Park Rangers but was Sherwood’s assistant last season, as he believes the 27-year-old has the talent to follow Luka Modric and Gareth Bale from Spurs to Madrid.

Ferdinand said: “We used to say to him: ‘You're the next person to go to Real Madrid, you're the next guy to go to Real Madrid from this club.’

“He’s got great ability, yet you just don't see enough of it. He leaves you frustrated because you know he's got more and you want to see it. He can get forward. He's got a great shot on him but you just never see it

“We used to watch him in training. Every time he got the ball he wanted someone to challenge him and he’d get past them, but then just pass it sideways,” the former England forward added on ITV.

Dembele is unlikely to be in the starting XI for Sunday’s Premier League match at Swansea, with Pochettino expected to make a number of changes to the side beaten 1-0 at Besiktas in the Europa League last night.

The result was not especially damaging as Tottenham had already qualified for the knockout stages. Pochettino will, however, be desperate for his players to shake off the Europa League malaise that has seen them lose four of the games that have followed European fixtures.

If Swansea midfielder Gylfi Sigurdsson proves decisive on Sunday, it will lead to more questions about Tottenham’s transfer policy.

Since Sigurdsson was allowed to return to Wales as part of the deal that brought Michel Vorm and Ben Davies to White Hart Lane, he has performed very well, enjoying the regular playing time he was rarely granted at Spurs.

Although Sigurdsson has no regrets about his time in north London, he admits there were difficulties during his two years there.

“It was a time that I really enjoyed, even though it was mentally hard over a couple of months,” said the Iceland player. “I played in some big London derbies, some Europa League games and with some great players, so I really enjoyed it. In football sometimes you have to make changes. I’ve changed and I’m very happy.”