Queen's, the traditional pre-Wimbledon warm up tournament, will take on added importance for 2015 after it was upgraded to an ATP 500 event.
With Wimbledon now a week later to give players more time off after the French Open, Queen's has been rewarded with a strong line up, including former champion Andy Murray, newly crowned Roland Garros king Stanislas Wawrinka and Rafael Nadal
But the trio may have to find their way past defending champion Grigor Dimitrov if they want to lift a trophy in south-west London before moving on to SW19.
Dimitrov aiming to repeat the success of 2014 and the sixth seed is not worried by the strong line-up.
"It doesn't change much," he said. "I am here to play whoever is on the other side. I am not going to lie, the draw is really unbelievable. If you think about it, all the guys have been playing good tennis and all of them are high-profile players.
"That is the beauty of it and I like to take on challenges like that. I know I don't have an easy draw. But I always like my chances anywhere I play. I am here to defend it; I am not here to just come out here and just hope that I play a good match."
Murray triumphed at Queen's in 2013 and went on to win Wimbledon that year, and a solid tournament could provide momentum for another challenge for the world's most prestigious Grand Slam.
"I always treat this week as being important," he said. "Some years I haven't played well here and then had a good run at Wimbledon, and sometimes I have played well here and not done as well at Wimbledon.
"I don't think that if I win this tournament it doesn't guarantee I am going to win Wimbledon. It does show that you have form on grass and also playing four or five matches is a lot more than some of the players get going into Wimbledon. If you can do well here, it definitely helps your confidence and sets you up well for Wimbledon."
Meanwhile, third seed Milos Raonic said he was pleased to be back in action after missing the French Open with a foot injury.
"It is amazing to be back," he said. "You really start to appreciate once you start missing a few big events. Missing Rome and obviously a Grand Slam at Roland Garros that was difficult for me. I am here, trying to make the most of the opportunities I had trying to find my game, try and play the best that I can."