German \'Gorilla\' Andre Greipel will look to continue narrowing his significant stage victory deficit to Tour de France sprint rival Mark Cavendish on the race Monday. As the yellow jersey contenders prepare to take their battle for overall victory up to the high altitude of the Pyrenees, stage 15 gives the non-climbing fast men of the peloton a rare chance to shine this week. Greipel, who claimed his third win of this year\'s race on Sunday to match Slovakian Peter Sagan\'s three-stage haul from this edition, is hoping to make it four on what will be his 24th birthday. \"It\'s my birthday on Monday, so obviously I\'d like to win again,\" said Greipel, nicknamed the Gorilla for his imposing physique. But two days after successfully negotiating the Mont Saint Clair -- a climb which snagged many of his rivals, including 21-times stage winner Cavendish -- Greipel\'s Lotto team could have a load of work on their hands.  The 15th stage begins in Samatan at the foot of the Pyrenees, ending in Pau 158.5 km later at the end of a 600-metre long home straight that is bunch sprint-friendly. Although relatively short, the undulating terrain through the Gers department will lead the peloton towards some hillier terrain as the Pyrenees approach. And that is where the sprinters\' teams could face their biggest test. None of the three small climbs that fature in the final 50 km are difficult -- at only 2.1, 1.9 and 1.5 kilometres long, most of the sprinters should sail over them. But they come in quick succession, providing a platform for late attacks that could go all the way. On the other hand, the summit of the final climb, the Monassut-Audiracq is 29.5 km from the finish, giving the chasing teams a chance to reform and launch a pursuit. One rider who could be looking to get in the breakaway is Spaniard Luis Leon Sanchez. The Rabobank rider launched a late attack in Saturday\'s stage won by Greipel, only to be caught when yellow jersey holder Bradley Wiggins came flying round a final bend in a bid to lead out Norwegian teammate Edvald Boasson Hagen. The Spaniard later griped that Wiggins\' Sky team, who have ben racing hard to defend the yellow jersey, had been greedy. But Wiggins has not ruled out a similar manoeuvre. \"I love him, he\'s a fantastic guy,\" Wiggins said of Sanchez, a former Paris-Nice winner who has won three stages on the Tour. \"It\'s unfortunate, but I can\'t look after everyone in the peloton. Edvald has done a lot of work for me throughout the race, and this season, and it was time to pay him back.\"