The Dutch goalkeeper has been in excellent for the Magpies this term, alerting a number of big European sides.
Interest from Serie A is thought to be high, with AC Milan keen to lure him to the San Siro.
Alan Pardew is desperate to keep his stopper, but is aware that the appeal of a switch to a club of such stature will be difficult for Krul to pass on.
As a result, he is looking at potential replacements, with Ruddy at the top of his wish list.
The Canaries ace has been one of the Premier League’s most consistent glovesmen in recent years, and has been influential in keeping the East Anglian outfit in the top tier.
Ruddy rejected a rumoured switch to Chelsea over the summer amid fears of a lack of playing time, but could be tempted by Newcastle if Krul is out of the picture.
The 27-year-old has serious ambition to be a part of the England set-up, and his chances may be boosted if he is playing regularly for one of the country’s most famous club sides.