Mauricio Pochettino has been appointed Tottenham Hotspur’s manager on a five-year contract after resigning at Southampton and Spurs are now seeking to reunite the Argentinian with his former captain, Adam Lallana, at White Hart Lane.

The former Espanyol head coach had made clear his desire to leave St Mary’s after 16 months to replace Tim Sherwood, who was sacked after the final game of the season with Spurs having qualified for the Europa League courtesy of a sixth-place finish. Tottenham had considered the Ajax manager, Frank de Boer, having lost out on Louis van Gaal to Manchester United, but had long since earmarked Pochettino as their favoured appointment.

A deal was agreed in principle last week, though agreeing compensation with Southampton, where the 42-year-old had 12 months to run on his contract, did briefly see an announcement delayed. Saints were due around £2m to cover the final year of Pochettino’s deal and that figure is understood to have been settled by the departing manager. He will be joined at Spurs by his assistant head coach, Jesús Pérez, the first-team coach Miguel D’Agostino, and the goalkeeping coach Toni Jiménez, with whom he has worked at his last two clubs.

“In Mauricio I believe we have a head coach who, with his high-energy, attacking football will embrace the style of play we associate with our club,” said the Tottenham chairman, Daniel Levy, who will now have worked with 10 managers over 13 years at the club. “He has a proven ability to develop each player as an individual, whilst building great team spirit and a winning mentality. We have a talented squad that Mauricio is excited to be coaching next season.”

Spurs will expect Pochettino to get more out of a squad who were revamped dramatically last summer following the sale of Gareth Bale to Real Madrid for a world record £86m. Roberto Soldado, Vlad Chiriches, Etienne Capoue, Nacer Chadli and even Paulinho offered only glimpses of their talent in their first campaign in England, while Erik Lamela – a record £30m arrival from Roma – did not even grant that. Only Christian Eriksen of the new arrivals made a favourable impression.

Yet while Pochettino will be charged with bringing more out of the present crop, his compatriot Lamela in particular, there remains scope to add to the team’s options. Spurs have long admired Lallanas progress at Southampton and watched the England midfielder become the subject of a £20m bid from Liverpool this month, with Southampton seeking considerably more for him. Liverpool believe the player’s wish is to join them, though Spurs will explore their own chancesin the hope Pochettino’s influence could sway his decision. Tottenham are also interested in the Standard Liège forward Michy Batshuayi, whose contract contains an £8m release clause, and have first option to resign Steven Caulker from Cardiff City.

“This is a club with tremendous history and prestige and I am honoured to have been given this opportunity to be its head coach,” Pochettino said. “There is an abundance of top-class talent at the club and I am looking forward to starting work with the squad. Tottenham Hotspur has a huge following across the world and I have great admiration for the passion the fans show for this team. We are determined to give the supporters the kind of attacking football and success that we are all looking to achieve.”

Southampton had offered the Argentinian a new contract in the aftermath of their impressive eighth-place finish to the recent campaign and have been left disappointed, if defiant, by his decision to move on. While Pochettino was undoubtedly unsettled by the departure of the club’s influential chief executive, Nicola Cortese, in January, he had been unconvinced that the owner, Katharina Liebherr, could match his own ambition with bids having been submitted for a number of key players.

Aside from Lallana, Luke Shaw is the subject of strong interest from Manchester United and Chelsea, while Liverpool have inquired about Dejan Lovren and Arsenal have been strongly linked with the French holding midfielder Morgan Schneiderlin. “The club has been on a constant path of growth since the arrival of Markus Liebherr in 2009,” said the Southampton chairman, Ralph Krueger. “This growth took place before Mauricio came, it continued strongly under his leadership, and it will continue into the next season. The board’s job is to find opportunity in this challenge and to continue to move the club forward. We have begun the search for a new high-calibre manager. We will be looking for a manager that shares our values, our principles and our philosophy. A manager who can continue to grow the first-team and build on our strong foundation.”

Southampton’s short-list will include the former Basel coach, Murat Yakin, who has impressed in winning the Swiss title in each of his two seasons as manager. He departed by mutual consent earlier this month having taken the team to the Europa League semi-finals in 2013 and the quarter-finals this year.

Michael Laudrup and Oscar García, both without a club after leaving Swansea and Brighton, are also under consideration, though Derby County’s Steve McClaren is apparently not in contention for the role.