Serena Williams will rest for a week after withdrawing from the Swedish Open due to an elbow problem but is confident the injury will not derail her preparations for the US Open. Williams, who will bid to complete a rare calendar grand slam at Flushing Meadows, withdrew ahead of her second-round match against Klara Koukalova after sustaining the injury during practice. 'As much fun as we have been having the past 8 or so weeks I have to take some time to let my elbow heal,' Williams said in a post on her Facebook page. 'I am confident it will be ready for the rest of the summer. I need some time to recover and rehab it, but as of now I am being forced to take the next week off.' The 33-year-old, who won her sixth Wimbledon singles tennis title this month, is scheduled to defend her title at Stanford from Aug. 3 and play the Rogers Cup in Toronto the following week ahead of the US Open, which starts on Aug. 31.