The former Stuttgart man has been deemed surplus to requirements in West London following the arrival of veteran Brazil defender Thiago Silva and the Blues are open to selling the German defender according to recent media reports.
Rudiger is yet to feature in any of Chelsea’s opening three games of the season, as the likes of Paris Saint-Germain and Barcelona are said to be mulling over the possibility of securing his services.
Keown has warned against selling the 27-year-old as he thinks Rudiger still has much to offer in Chelsea.
“The goals they concede, they don’t seem to know how to mark properly from crosses,” he told talkSPORT.
“We’re asked to analyze now in this job, to look at the detail; have a look at Chelsea’s line.
“I’ve spent hours watching, their defense is a joke, it’s a disgrace!
“Silva’s come in, maybe he’ll resolve that, but I think Rudiger is actually their best defender”
“He’ll perform better with somebody alongside him telling him the craft of how to mark from crosses – which is where they conceded a lot of goals last season.
“Defending has gone out the window in the Premier League at the moment, by the way, but there are elements of Chelsea’s team at the back that are not quite right.
“They’re not in position early enough and that’s because they go to sleep.”
Keown was asked to mention who to partner Silva in the heart of Chelsea defence, and without mincing words he chose Rudiger.
“I would go Thiago Silva alongside Rudiger.
“I know Rudiger has a problem from set pieces, but they all do. Kurt Zouma is maybe a better header of the ball, but he’s also prone to mistakes.
“I think Rudiger is their best defender, and that is the long-time partnership. But, it looks like Rudiger is going out the door!”