Andy Murray is now the British men's number 23 after he dropped to 839 in the world rankings following his injury problems.
The former world number one fell 690 places in Monday's rankings after he pulled out of Wimbledon.
The 31-year-old had hip surgery in January after being out of action since last year's Wimbledon.
He has only played three matches since then, winning one at Eastbourne last month.
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Murray is due to return to action at the Citi Open, which starts in Washington on 30 July.
He also hopes to play Masters level events in Toronto and Cincinnati before the US Open, which begins on 27 August.
Murray will be able to enter the Masters events under the exemption available to players coming back from long-term injury.
His current position in the rankings sees him alongside part-time US College and Challenger Tour players.
British number one Kyle Edmund is up to a career-high 16th, followed by Cameron Norrie (77) and Liam Broady (177).
Also ranked above Murray are Jay Clarke (225), Dan Evans (323), James Ward (333), Alexander Ward (338), Edward Corrie (446), Tom Farquharson (479), Brydan Klein (498), Lloyd Glasspool (538), Jonathan Gray (589), Billy Harris (679), Ryan James Storrie (698), Luke Bambridge (706), Oliver Golding (728), Evan Hoyt (745), Neil Pauffley (746), Ryan Peniston (769), Finn Bass (787), Richard Gabb (811) and Luke Johnson (825).