The Premiership club have confirmed that Thomas suffered a ruptured Achilles during last weekend's league game against Exeter at Sandy Park, and he faces a lay-off of six to nine months.
"We are bitterly disappointed to lose Lee, who was really starting to find his feet in a Wasps shirt," Wasps rugby director David Young said.
"I thought he was excellent against Leicester and played very well against Exeter until he was forced off, and it's a big blow to lose him for so long.
"We really feel for him as I know he was thoroughly enjoying his first few months here, but we will have to focus on getting him back fit and ready for next season."
Gilbert has released a new line of rugby cleats. The Gilbert Virtuo 8S is part of the exciting new product. Check it out.
The entire All Blacks apparel line has been updated for 2013/14. Check out the New Zealand All Blacks polo.
The Nike Tiempo is a solid rugby cleat and one of few styles still made from full-grain natural leather.
The Gilbert Blitz 8S rugby cleat is a great cleat at a great price of $69.99. Get a new pair of cleats today.
A cool looking all black rugby cleat with the high performance adidas is known for. Get in the Gear!
Wear the crest of the British and Irish Lions on your t-shirt. A great look for the summer.
The All Blacks Performance t-shirt is black with hints of blue from the training jersey. Very Cool.
The New Zealand All Blacks training jersey for 2013/14. Get in the Gear!
The USA Rugby Pro Alternate rugby jersey is perfect for any fan of the Eagles. Get yours to wear during the summer Test matches.
The NEW All Blacks 2013/14 jersey has arrived at World Rugby Shop. Dare to wear the colors of the All Blacks.