A video has emerged of the former British number one suffering the direct hit during the event held to mark the launch of the facility in Portsmouth, Hampshire.
The 40-year-old, who was born in Montreal, Canada, but who played for Britain, joined hundreds of youngsters and adults who attended free coaching sessions at the event held on January 11.
And his expert tips appeared to pay off for one young boy, who struck a fine forehand, with the ball hitting Rusedski straight between the legs.
Jo Dallas, centre manager, said: "Greg Rusedski came down to officially open the new tennis centre and he was a great sport, happy to spend time with everyone.
"It was a bit unfortunate with the incident on the video but he took it well."
The modern facility hosts four indoor courts, six outdoor courts and eight indoor mini tennis courts for the budding enthusiast or the more experienced player. The centre was completed in November, and has been a resounding success so far, with 1,100 tennis enthusiasts already through the door.
Portsmouth City Council secured £834,387 from the Lawn Tennis Association (LTA) towards the cost of the centre, with the additional £332,824 sourced from council funds.
Since 2011 Portsmouth has been supported as one of eight Tennis Foundation and LTA community tennis pilots designed to test what works best to grow tennis at a local level.
Councillor Lee Hunt, Portsmouth City Council's cabinet member for culture, leisure and sport, said: "Just like Greg Rusedski, tennis in Portsmouth is a big hitter, with more and more people getting involved.
"After the Olympic gold medal success and Wimbledon victory for Andy Murray, plus silver in the mixed doubles with Laura Robson, and American Open Grand Slam win, alongside many worldwide junior winners, this is a really exciting time for British and Portsmouth tennis.
"By working with British Tennis and city partners, our city council is helping to create facilities which rank amongst some of the best for 'grassroots' players in the UK. We're hoping to encourage people who may not have tried tennis before to come along and have a go."