Every men's semifinalist at Wimbledon has displayed a great sense of perseverance so far in advancing past the first five rounds at the All England Club, but that doesn't mean there aren't still questions about them winning the Grand Slam.
The elite level of competition combined with difficult court conditions has turned one of the most prestigious tournaments in tennis into an all-out battle of attrition. It's a battle that all four men's semifinalists have embraced and conquered.
However, they all still have questions that they must answer if they want to punch their ticket to the finals.
Here's a look at the biggest question for each.
Andy Murray: Will He Fall Behind Early Again?
Andy Murray comes into his match against upstart Polish phenom Jerzy Janowicz as a favorite. However, as evidenced by Murray's quarterfinals matchup against Fernando Verdasco, that doesn't mean that he's unbeatable.
The local favorite fell behind early in his match with the big-serving Verdasco, dropping the first two sets, 4-6, 3-6. Verdasco won the first set despite making 15 unforced errors, a number that Murray should have been able to capitalize on.
Murray was able to get back to top form by the end of the match, rallying to win the last three sets and reach the semifinals, but Janowicz again presents the challenge of a player with a big service game. If Murray falls behind this time, it will be much more difficult to mount a comeback.
Janowicz has dropped just two sets at Wimbledon.
Jerzy Janowicz: Is He Prepared to Win on the Big Stage?
Jerzy Janowicz has all the raw tools to become a consistent threat at Wimbledon (and other Slams for that matter). He's incredibly rangy, partly because he's 6'8", gets great power from his backhand and, most of all, he already has a dominant serve.
The 22-year-old has hit 140 mph with his serve and has racked up 94 aces at the tournament—31 more than anyone else in the entire field. He has earned 84 percent of his first serve points and has rode that advantage into the semifinals.
The only question that remains is if he's ready to make the leap.
Reaching the semifinals is an impressive feat for the rising star, but getting to the Wimbledon final is another conquest entirely. Just ask Janowicz's opponent—Murray, who went to three straight Wimbledon semifinals before making it to the finals last year.
Novak Djokvovic: Does His Recent Loss to del Potro Mean Anything?
Novak Djokovic isn't just enjoying dominance at Wimbledon, he has been on fire throughout 2013.
Only five players have figured out a way to beat the Serbian superstar this year. Unfortunately for him, one of those five is his next opponent in Juan Martin del Potro.
The crafty Argentinian found a way to beat the Djoker at Indian Wells back in March, 4-6, 6-4, 6-4, but does that mean that del Potro can repeat his performance?
If Djokovic's run through Wimbledon is any indication, the answer is no. Tommy Haas defeated him at the Sony Open, but couldn't keep Djokovic from beating him in straight sets at Wimbledon.
Juan Martin del Potro: Is He Healthy Enough to Win?
Del Potro wasn't a favorite to get to this point, but he's certainly proved that he belongs. His run through the tournament includes impressive straight-set victories over both David Ferrer and Andreas Seppi.
However, del Potro's great play may not be enough if his knee isn't in top shape. Del Potro has struggled with his knee injury at the tournament and even considered pulling out against Ferrer, per Wimbledon's official Twitter feed.
Djokovic has been absolutely dominant through five rounds. He has yet to drop a single set and is primed to put another Grand Slam trophy on his mantel. Del Potro is going to have to be completely healthy if he's going to pull off the upset.
Can his knee hold up for a five-set match?