Boris Becker once shared a bitter rivalry with Ivan Lendl across the net and now the two former world number ones will try to outwit each other from courtside after the German’s shock appointment as coach to Novak Djokovic.

After Djokovic was named ITF World Champion for 2013, despite being overshadowed by Spain’s Rafa Nadal, Serbia’s world number two announced the first shake-up of his team since a short and unsuccessful spell with Todd Martin in 2009.

Djokovic’s decision to work with 46-year-old Becker means two of the current “Big Four” are now coached by former greats with Lendl helping Britain’s Andy Murray to the 2012 U.S. Open title and this year’s Wimbledon crown.

“I am really excited to have the opportunity to work with Boris,” the 26-year-old Djokovic said in a statement on his website (www.novakdjokovic.com).

“He is a true legend, someone who has great tennis knowledge and his…