Tottenham have strengthened their defensive ranks with Toby Alderweireld – but how did they pip Southampton to the Atletico Madrid man’s signature?

Belgium international Alderweireld spent last season on loan at St Mary’s and, according to Saints boss Ronald Koeman, had indicated to the club he was keen to make the move permanent this summer.

Instead, Alderweireld has put pen to paper on a five-year deal at White Hart Lane, where he will play alongside international team-mate Jan Vertonghen in Tottenham’s back four.

Here, we look at how Alderweireld’s move to Spurs happened – and how Southampton missed out…

Southampton sign Alderweireld on season-long loan from Atletico

Alderweireld joined Southampton on a season-long loan in September 2014. The 25-year-old had struggled to pin down a starting spot during Atletico Madrid’s title-winning 2013/14 campaign, making just 12 appearances after a 2013 switch from Ajax. The promise of first-team football at St Mary’s, following the departure of Dejan Lovren to Liverpool, attracted the Belgian.

“Southampton put a lot of effort in to get me, so now I want to give something back to the club by doing my best to help the team. I want to give everything for Southampton,” he said.

Alderweireld impresses for Saints

Alderweireld's impressive start to life at Saints was interrupted by injury in January

Alderweireld may have been unable to prevent Southampton losing 1-0 at Tottenham in October, but the centre-back had recorded seven clean sheets in 15 games by New Year’s Day with the Premier League’s meanest defence. The Belgian’s form sparked speculation Saints were primed to tie him down to a permanent four-year deal in the January transfer window, however, a hamstring injury in a 1-0 win at Manchester United sidelined Alderweireld until March.

Alderweireld happy at St Mary's as Pochettino plots defensive recruits

As Alderweireld returned to action, the Belgian suggested he would be happy to extend his stay on the south coast. “If I could choose then of course I would like to stay here," he said. "It's not up to me and Atletico could decide that they want me back. I'm enjoying the Premier League, I'm enjoying playing for Southampton - I love the club and I love the supporters.”

Meanwhile, in north London, Tottenham boss Mauricio Pochettino was openly critical of his defence, which had conceded 15 in their last seven, including three against relegation-threatened Leicester, and revealed it was an area he was planning to address.

“It's true, I was angry with the defending against Leicester and I am not happy about our record,” he said. “This is one thing we need to improve in the future.”

Atletico keen on Alderweireld

Alderweireld’s story took a new twist in April when Atletico Madrid’s sporting director Jose Luis Perez Caminero said the club were “counting on” the defender for next season.

The Spanish side had seemed happy to move on their £6m signing from Ajax, but Alderweireld's form at Southampton appeared to have led the club to rethink their plans.

“Alderweireld is finishing a very good season with Southampton and we are counting on [him] for the next campaign,” said Caminero.

Alderweireld's performances for Saints attracted interest from top clubs

Saints well-placed, says Alderweireld - but a Vertonghen link-up is tempting

For Alderweireld, though, his heart seemed set on Southampton – and the Belgian suggested Koeman’s side were best-placed to secure his services in the long run.

“Southampton are in a good position because I know the club,” he said. “They are very good to me. I did a great job for them as well so we have a good connection. I really like the Premier League.”

However, as speculation grew that Tottenham could be interested in a move for the Belgian, Alderweireld was asked about the prospect of playing alongside his international and former Ajax team-mate Jan Vertonghen…

“It would be very nice to play again with Jan,” he said. “The interest [from Tottenham] has yet to be concrete and finally Atletico must let me go. Atletico will decide my future, but I would like to stay in the Premier League. That some of the big clubs show interest proves I'm doing well.”

June sees assurances made and a key deadline pass

After helping Southampton to a seventh-place finish in the Premier League, Alderweireld gave Southampton assurances he was keen to commit to the club on a permanent deal, should they come to an agreement with Atletico Madrid, according to Koeman.

However, although Southampton could have completed a transfer for around £6.9m in June, Atletico allowed the deadline to pass and started negotiating with Spurs – who were seemingly prepared to offer a lot more.

It has been reported Atletico would need to buy Alderweireld out of their agreement with Southampton for a fee of £1.5m in order to be able to sell him to another club – something which was not done within the time-frame set out in the agreement, raising speculation Southampton may seek legal action against Atletico.

“What came out in the press, that Southampton signed an option to the player and Atletico Madrid is trying to pay back the option and our knowledge is that it is, and was, too late,” said Koeman.

Spurs chairman Daniel Levy completed an £11.5m deal for the defender

A late bid is ignored as Levy and Spurs seal the deal in July

Irrespective of speculation around Atletico and Southampton’s agreement, Tottenham chairman Daniel Levy flew to Madrid at the weekend to negotiate with Atletico, according to newspaper reports.

The Spurs supremo returned a happy man, with a £11.5m bid accepted by the Spanish club and Alderweireld was at Tottenham on Tuesday to complete his medical.

Meanwhile, on the south coast, Koeman gave a press conference, in which he said he hoped the defender may yet still come to Southampton.

“What happened with Tottenham in the middle I don’t know – seriously, I don’t know what happened. But [executive director of football] Les Reed is working on that situation and I will wait for more news about the situation of Toby,” he said.

“Of course [I want Alderweireld to sign for Saints]. And the player told us the same. I mentioned that we had a talk to Toby last season, before then and not this season, and he was very happy about Southampton and we mentioned to the player that we like to continue with the player and that was the case to Atletico Madrid. What happened after I don’t know.”

Later on Tuesday evening, Southampton submitted a £14.2m bid to Atletico in a last-gasp effort to secure Alderweireld’s services – and heard nothing back.

Southampton could have signed him for as little as £7m. They really thought Alderweireld would stay on but he’s now a Tottenham player. Aidan Magee

On Wednesday morning, Tottenham announced they had completed the signing of Alderweireld, with the player saying: “I’m very proud to become a Spurs player. It’s a big club and it’s always been a dream to play at a club like Spurs. Now that dream is coming true so I’m very happy.”

Southampton may have lost the battle for Alderweireld’s signature but the transfer saga is not necessarily over yet, according to Sky Sports News HQ’s Aidan Magee.

“It may not be the end of this because Southampton may still pursue some of that fee from Atletico after they missed the deadline to remove Southampton’s option to buy,” he said.

“Southampton could have signed him for as little as £7m. They really thought Alderweireld would stay on but he’s now a Tottenham player.”