The Spaniard was one of Newcastle's stars last season and his form has alerted the La Liga and Champions League holders as they seek defensive reinforcements.
Captain Carles Puyol is unlikely to be fit for the start of next season after knee surgery, and manager Pep Guardiola is not keen to persist with midfielder Javier Mascherano as a stand-in centre-half.
The signing of Enrique would allow him to switch Eric Abidal to the heart of the defence with the Toon ace slotting in at left back.
A 'THANK YOU' TO FOOTYMAD READERS ...
'MAGPIES IN EUROPE'
FOR £5.99 (inc post)
2010/11 has been NewcastleUtd-Mad's greatest season for page 'hits', and as a thank you to all readers we are giving you the chance (FOR TWO WEEKS ONLY) to purchase "MAGPIES IN EUROPE" for £5.99 (and that includes the postage).
*Normal price is £9.99
OFFER ENDS JUNE 10th 2011
Although "Magpies In Europe" will not be launched OFFICIALLY until next season ... if you want a copy it is available NOW from this website ... and ONLY from this website!
FOREWORD BY FAIRS CUP HERO JOHN McNAMEE
Sports Journalist Richie Everson: "At last a book that the fabulous Newcastle United fans can relate to. It's informative, all the facts and figures are there, plus the 120 match reports from all the fixtures ... but it is the articles by the supporters that amazed me.
"I went to many of those games, and this is the only book I can honestly say 'hits the nail on the head'!
"Yes we know the results and the scorers, but some of the facts in this book had me so wrapped up in it I couldn't put it down.
"Was Benny Arentoft cup-tied when he played in the final? Big Wyn and his battle with John McGrath; McFaul scoring a penalty when the crowd had gone home; the trouble in Palermo; it is all amazing stuff.
"I would honestly give this book 10 out of 10."
MAGPIES IN EUROPE
From Antwerp to Zurich
Please include your address in a letter and send a cheque (or postal order) for £5.99 payable to Mr K Fletcher, to:
'MAGPIES IN EUROPE', K Fletcher, 5 Dunelm, Sacriston, Co Durham DH7 6NU.
Or contact: Kevnumad@fsmail.net