Rafael Nadal will move ahead of Roger Federer in the rankings. Getty

What a difference a year makes.

With the U.S. Open, the final Grand Slam of the year, set to get underway on Aug. 28, the ATP rankings have seen some big changes in the top five due to injuries. Next week, Rafael Nadal will return to No. 1 for the first time since July 2014, leapfrogging Andy Murray and distancing himself from Roger Federer.

Injuries have played a big role among the world's top players. Murray (hip) and Federer (back) both withdrew from the Cincinnati Masters, prompting Nadal to move up. Novak Djokovic, who has battled injuries this year, decided to shut down his season in July to fully recover from an elbow injury. Stan Wawrinka, who has suffered from knee problems, also cut short his season.

It's been a big year for both Nadal and Federer after uneven results last year. At the end of 2016, Nadal was ranked No. 9, while Federer was ranked No. 16, with many wondering if the two legends may have lost a step. At the top, No. 1 Murray and No. 2 Djokovic were separated by just 630 points. Milos Raonic, who was ranked No. 3, trailed Djokovic by 6,330 points.

Nadal, 31, conceded that it's been "tough to get back to No. 1." He had spent a total of 141 weeks in the top spot, with 56 consecutive weeks at No. 1 between June 2010 and July 2011.

The clay-court specialist showed support for Federer, who described his back injury as a "tweak." The Swiss legend has enjoyed a big year, winning both the Australian Open and Wimbledon, providing additional intrigue ahead of the U.S. Open.

"Obviously, it's bad news for the (Cincinnati) event that Roger is not playing. For me personally obviously to be back to that position is something special," Nadal told reporters Monday.

After reaching the Australian Open final and cruising to his 10th French Open title, Nadal's comeback has been impressive after suffering through many setbacks in 2015 and 2016.

"A lot of things have happened since the last time I was in this spot," Nadal said. "Injuries and some tough moments, of course, but I have held the passion and the love for the game, and that's why I have the chance to be back in that position again. So I'm just trying to enjoy the moment and just trying to be ready to compete well here. That's the most important thing for me now."

Oddsmakers list Federer and Nadal well ahead of the pack for the U.S. Open. Federer remains the favorite to win at Flushing Meadows with his odds listed at +110, while Nadal has the second best odds at +250. Murray is listed at +500 and Alexander Zverev is fourth at +800.

Federer has won the U.S. Open five times. Nadal has won the tournament twice.

ATP Rankings (points)

1) Andy Murray (7,750)

2) Rafael Nadal (7,555)

3) Roger Federer (7,145)

4) Stan Wawrinka (5,780)

5) Novak Djokovic (5,325)