With last fall’s retirement of doubles specialist Rennae Stubbs, the Washington Kastles moved to shore up the core of their 2011 championship roster in Tuesday’s World TeamTennis draft.

Six key members of the undefeated 2011 squad return. Joining marquee players Venus and Serena Williams are doubles ace Leander Paes, the league’s 2009 and 2011 MVP; Bobby Reynolds; Arina Rodionova and coach Murphy Jensen.

In just their fourth season of competition, the Kastles won their second WTT title, becoming the first squad in the league’s 36-year history to do so with a perfect record (16-0).

The Kastles protected Rodionova, the league’s 2011 female rookie of the year, with their first-round pick in Tuesday’s draft. With their fourth-round pick they acquired her older sister, Anastasia Rodionova, ranked No. 22 in women’s doubles and a top-100 singles player, as well.

“Our top priority this season was to bring back the core of our squad that completed a perfect championship season and to add a strong women’s player following Rennae’s retirement,” Kastles owner Mark Ein said.

The Washington Kastles' Venus Williams returns a shot as her mixed doubles partner, Leander Paes watches during play against the Kansas City Explorers. (FOR THE WASHINGTON POST)

Paes, a former world No. 1 doubles player, completed a career Grand Slam earlier this year by teaming with Radek Stepanek to win the Australian Open. He returns for a fourth season with the Kastles.

The Kastles open the 2012 season July 9 at the Orange County Breakers. The team’s home opener at Kastles Stadium on the Wharf is July 12. Serena Williams will appear in the July 22 match against the Kansas City Explorers. Venus Williams is scheduled to appear in the home finale on July 24.