Sam Allardyce
Sunderland boss Sam Allardyce will hope to avoid another tense relegation battle in 2016/17Ian MacNicol/Getty Images

Survival specialists Sunderland flirted heavily with relegation once again in 2015/16, spending a total of 237 days marooned in the bottom three and never once occupying a position higher than 17th place. The decision to install Sam Allardyce as manager following the resignation of Dick Advocaat in October eventually proved decisive as the Black Cats ended the season on a six-match unbeaten run and retained their top-flight status for a 10th consecutive season at the expense of Norwich and fierce rivals Newcastle with a game to spare.

Despite the euphoria that followed those crucial victories over Chelsea and Everton, however, the club's hierarchy will be only too aware that they are sailing perilously close to the wind and one more season of underachievement could see their luck finally run out. Crucial to hopes of avoiding another nail-biting dogfight and reaching the relative comfort of mid-table security will be a positive summer in the transfer market. By escaping demotion to the second tier, Sunderland remain on the Premier League gravy train and as such will reap the rewards of the lucrative new television rights deal set to kick in next term.

Business so far

Allardyce, recently filmed dancing the night away to the sound of Rihanna during a well-earned holiday in Marbella, is yet to dip into the market either as a buyer or seller. According to the Evening Chronicle, the 61-year-old is looking to raid the French market again in search of new recruits after successful January deals for Lamine Kone and Wahbi Khazri.

What they need

Sunderland will likely look to strengthen in all departments, but top of the list should be the addition of at least one new proven striker.

The 33-year-old Jermain Defoe, who many feel was unlucky to miss out on selection for England ahead of Euro 2016, spearheaded their survival push with 15 goals but shouldered too much responsibility in the final third. Fabio Borini was their next highest scorer with just five. A record of 62 conceded suggests that defensive reinforcements would not go amiss, either.

Who could join

Diafra Sakho
Diafra Sakho has emerged as one of Sunderland's key summer transfer targetsGetty Images

In terms of increased firepower, recent speculation suggests that Sunderland are planning to complete a £10m ($14.5m) deal for West Ham striker Diafra Sakho. Swansea's Andre Ayew continues to be a player of significant interest, while defenders Neven Subotic, Steven Caulker, Charlie Taylor, James Tomkins, Rico Henry and Terence Kongolo have all been mentioned tentatively in connection with possible moves to the Stadium of Light. The club are also believed to have joined newly-promoted Middlesbrough in the race for West Brom midfielder James Morrison.

Steven Fletcher, Danny Graham, Jordi Gomez, Santiago Vergini, Liam Bridcutt, Emanuele Giaccherini, Adam Matthews, Will Buckley and Charis Mavrias are among the raft of loanees returning with seemingly little chance of re-establishing themselves in the first-team squad.

Who could leave

Steve Harper, Wes Brown, Valentin Roberge and Graham will all see their contracts expire this month and none of that quartet are expected to be retained. Fletcher, who scored twice during a somewhat bizarre spell with Ligue 1 outfit Marseille, is also available on a free transfer amid renewed interest from Scottish champions Celtic. Jeremain Lens has failed to impose himself and could leave just a year after his £8m switch from Dynamo Kiev.

Allardyce is reportedly eager to turn Yann M'Vila's season-long move from Rubin Kazan into a permanent arrangement, while Ola Toivonen and Dame N'Doye will return to parent clubs Rennes and Trabzonspor respectively. DeAndre Yedlin could rejoin from Tottenham Hotspur after a successful individual campaign on Wearside and Manchester United are said to be keeping a watchful eye on England U21 goalkeeper Jordan Pickford.

Yann M'Vila
Yann M'Vila is believed to be interested in staying at Sunderland beyond the end of his loan dealDavid Ramos/Getty Images

Former Liverpool centre-back Sebastian Coates has already seen his loan deal with Sporting CP extended until the summer of 2017, although it remains to be seen if Bridcutt will return to managerless Leeds United on a full-time basis. Matthews appears surplus to requirements after spending the latter stages of last season at Bristol City and Mavrias is expected to move to Fortuna Dusseldorf.

What the manager has said

"I think there'll be a massive turnover if we do the job right," Allardyce told the Shields Gazette. "There's lots of players here on loan or out-of-contract, so there's a question of what we do with them and how many we keep. There's also some of the players who we've already got who will say to me 'gaffer I'd prefer to move because you haven't played me as much as I'd want'. That's natural. I would expect them to say that.

"I haven't got a problem with that whatsoever. But like everything else as a manager, I'm a good wheeler-dealer. In and outs are a massive part of how successful you're going to be and hopefully our recruitment policy will be as good in the summer as it was in January."