Everton will face a fight to prise Gylfi Sigurdsson from Swansea City should the Swans avoid the drop this season.

Blues boss Ronald Koeman is a huge admirer of the Iceland international and a £28m approach was strongly rebuffed last summer.

Everton knew Sigurdsson was not for sale in January but he remains on their wishlist ahead of the next transfer window.

Koeman believes that if the Blues land his targets this summer then they can mount a sustained challenge for the top four next term.

Gylfi Sigurdsson of Swansea City. (Photo by Lynne Cameron/Getty Images)

Defender Michael Keane and Goodison old boy Wayne Rooney are among those interesting Koeman while Sigurdsson remains a firm favourite of Koeman.

Should Swansea suffer relegation then Everton鈥檚 chances of landing the 27-year-old will be boosted but if the Swans survive then it is understood it would be far from easy tempting him away.

Everton's Dutch manager Ronald Koeman (L) and Hull City's Portuguese head coach Marco Silva watch from the touchline during the English Premier League football match

Sigurdsson is believed to have enjoyed working with new Swansea boss Paul Clement and having endured a tough time at Tottenham Hotspur would need convincing about leaving the club.

A £35m bid from China was rejected by the Swans in January and the club鈥檚 American owners would be wary of cashing in on another one of their star names, especially after the reaction to losing Ashley Williams to Everton in August.

Swansea City manager Paul Clement during the Emirates FA Cup, Third Round match at the KCOM Stadium, Hull. Anna Gowthorpe/PA Wire.

Swansea are three points clear of the drop zone and have a better goal difference than Hull City in 18th.

Clement鈥檚 side face crunch games with Middlesbrough and Sunderland in their final nine games but also take on Spurs, Manchester United and Everton before the end of the season.