Andy Murray admits he will need to make a rapid improvement if he is to beat Janko Tipsarevic on Thursday and reach the quarter-finals at the AEGON Championships.
The British number one, who is nursing an ankle injury, made a winning start to his grass-court season on Wednesday night by scrapping his way past Xavier Malisse 6-3 5-7 6-3. Murray shares a 3-3 career record with 14th seed Tipsarevic and he lost to the Serbian at Queen's Club in 2006.
"I have played Janko quite a few times and he's tough. He normally plays better against better opposition. I think he's said that quite a few times," said Murray. "I think he beat Andy Roddick at Wimbledon and he had a very good match with Roger Federer a few years ago at the Australian Open. He'll be tough. I'll need to play better if I want to win."
Murray is trapped in a Catch-22 situation this week - and is has been stressing him out. The 24-year-old needs time to recover from a partially-torn tendon in his right ankle, which he rolled in the third round of the French Open.
But Wimbledon starts in less than a fortnight and Murray also needs time on grass courts in order to adapt properly from the clay surface at Roland Garros.
"It's been quite a stressful few days to decide because I was desperate to play here but also didn't want to end up messing up for Wimbledon," said Murray.
"It's a tough one. The situation we're in is you have very little time between now and Wimbledon, and you want to play matches on this surface. I want to play here, play as many matches as possible but I also want to go into Wimbledon pain-free.
"Playing on it is not exactly the best course of action to get an ankle better. Each day you play you may not be making it worse, but it's also not making it go away.
"If this tournament was irrelevant then I wouldn't be playing. But it is relevant so the fact is that I'm here trying to play as many matches as possible."
After Murray, French Open champion Rafael Nadal takes centre stage against Radek Stepanek and then British number two James Ward will tackle defending champion Sam Querrey. Ward recorded the biggest victory of his career in the last round when he beat Stanislas Wawrinka, who is ranked 202 places above him in the world.