ELLIS SHORT will give the green light to more than £25m of summer investment after his financial assurances helped persuade Dick Advocaat to perform a surprise U-turn and return to Sunderland.

Advocaat’s reappointment on a one-year contract was confirmed yesterday afternoon after a whirlwind 24 hours in which the Dutchman reversed his previous decision to walk away from Wearside in the wake of last season’s successful survival bid.

While Lee Congerton began pursuing alternative options as soon as Advocaat announced his initial intention to reject Sunderland’s offer of a new deal, the Black Cats sporting director continued to push the 67-year-old to change his mind.

His persistence was eventually rewarded when Advocaat relented on Wednesday night, and a 12-month deal was swiftly agreed yesterday.

Having previously claimed that personal matters were preventing him from returning to Wearside, Advocaat is understood to have held a series of heart-to-heart discussions with his wife, Dieuwke, which resulted in a sudden change of heart.

However, having previously claimed that “five or six quality signings” were essential if Sunderland were to avoid another relegation battle next season, the Dutchman also sought assurances about the level of financial investment that was anticipated this summer.

Short has pledged to support Advocaat’s transfer plans, and there is an expectation that around £25m will be available once the transfer window formally reopens.

“After a lot of discussions with Ellis and Lee, they convinced me that I’m the right man for the club,” said Advocaat. “It was a great feeling to be part of Sunderland in the last few months, the experience was something very special, and after talking with Lee, Ellis and of course my family, we all agree it’s the right decision.

“The owner is willing to make resources available. They think I’m still fit enough and personally I also feel that I’m still fine. It’s a wonderful club.”

A series of potential targets have already been discussed as part of Advocaat’s talks with Congerton, and it is expected that plans will be finalised at the start of next week.

The acquisition of a centre-half and centre-forward is regarded as a priority, with Celtic’s Virgil van Dijk understood to be at the top of Advocaat’s wanted list.

Van Dijk will leave Parkhead this summer, and while Celtic are hoping to receive around £10m for the 23-year-old, it is expected that he will eventually leave for closer to £6-7m.

Advocaat’s existing contacts in Holland and Serbia will make both of those markets of obvious interest, with Congerton willing to grant the head coach a high degree of autonomy when it comes to the identification of targets.

Advocaat, who will be accompanied by first-team coach Zeljko Petrovic and is expected to retain Bert van Lingen as his number two, will also make an early decision on Anthony Reveillere and Wes Brown, the two senior players whose contracts are due to expire at the end of the month, and Lee Cattermole, Steven Fletcher, Adam Johnson and Danny Graham, who are all about to enter the final year of their current deals.

His decision to return to Wearside reflects a confidence that a repeat of last season’s relegation battle can be avoided, and has been rapturously received by Sunderland’s fans, who serenaded Advocaat in emotional scenes after the final whistle of the goalless draw at Arsenal that confirmed the club’s top-flight survival.

“Dick’s credentials in football are top class and we saw what an impact his vast knowledge and experience had on our team and the club as a whole in just two months,” said Short.

“Sunderland fans took him to their hearts and so did everyone at the club, so we are absolutely thrilled that he will be here longer term.”

Advocaat’s willingness to sign a one-year deal means the Sunderland hierarchy can use the next 12 months to sound out a potential successor and ensure they are not left in the lurch again next summer.

Congerton tried to persuade Paul Clement to move to the Stadium of Light last week, but the former Real Madrid assistant was unwilling to renege on a previous commitment to take over at Derby County.

Attention then switched to the continent, with former Stuttgart boss Armin Veh and ex-Real Madrid chief Bernd Schuster both approached as potential options, but the search for a new boss was always running hand in hand with an ongoing effort to persuade Advocaat to return for a second spell.

“Dick was always our number one choice and we were determined we weren’t going to take ‘No’ for an answer,” said Congerton. “I have been in constant contact with him over the last two weeks and I’m absolutely delighted that he has agreed to return.

“In just a short space of time he has bought into the club whole-heartedly and understands exactly what we need now in order to move forward. We have a lot of work to do to prepare for the season ahead, and that starts in earnest now.”

Sunderland’s players were keen for Advocaat to remain, and skipper John O’Shea was the first to voice his approval at yesterday’s developments.

“The boss came in last season and lifted everybody at the club – players, staff and fans,” said the defender, who is currently in Ireland preparing for Sunday’s friendly with England. “He got the best out of everybody, giving the team the confidence and belief that we could stay in the top-flight.

“He knows the club, what is needed and how we can push on to the next level. The fans love him too, so I’m sure it will be a season that we can all look forward to.

“We all know there is a lot of work to be done over the summer, and with new faces added during pre-season, we can all push on together.”