The world cup is upon us, and the hopes of nations ride upon the backs, shoulders and legs of some of the world's best players. This year, the competition for the worlds biggest trophy is wide open. But as in any sport, the health of star players is crucial if you want to get the win. So who are the big injury concerns coming into the World Cup? 

3 Crucial World Cup Football (Soccer) Players Returning from Injuries

Mohamed Salah - Liverpool/Egypt  - Shoulder Injury

Forward "Mo" Salah was an absolute revelation for Liverpool this year, both domestically in the Premier League, and abroad during Liverpool's scintillating run to the Champions League finals. Salah showed his mouth-watering potential with stints at Chelsea and Roma, but anyone who says they saw this incredible season coming is fibbing.

Even the most optimistic fortune teller couldn't have seen Salah breaking the Premier League record for goals and leading the Reds to within a game of European glory.

Alas, Salah suffered a shock shoulder injury in the first half of the final against Real Madrid when famed agitator/defensive stalwart Sergio Ramos violently jerked Salah backwards, causing a dislocated shoulder. He had to sit out the rest of the final, and Liverpool went on to lose to the Real juggernaut. 

Now on to the World Cup. Salah's injury is a critical wrinkle in the Egypt's World Cup chances. If he is fully recovered, they have the chance to beat any team on a given day. If not, it could be a quick out.

Eden Hazard - Chelsea/Belgium - Leg Injury

Eden Hazard is the straw that stirs the drink for Chelsea. When he's playing up to his potential, he's unstoppable, conjuring up comparisons to the World's greatest midfielders. But to say he's mercurial would be an understatement. Hazard seems to turn it on and off at will - but sometimes it's not apparent if he's actually willing.

The same goes for Belgium. Stacked with a squad that includes such talents as Lukaku, Mertens, and Courtois, the Belgians are poised for another deep run at the World Cup. But Hazard is the one who runs the offense, and unfortunately, he was escorted off the field after a collision during a friendly match with Costa Rica in the lead-up to the tournament.

The Belgian coaches are downplaying the injury, but you'd better believe the world will be watching to make sure Hazard is fit during the tournament. If he isn't, the Belgians might have a tough time fulfilling their vast potential this year.

Marcus Rashford - Manchester United/England  - Undisclosed Injury

Manchester United is always fully stocked when it comes to talent. Sometimes they buy the world's best by paying exorbitant transfer fees. And sometimes they use home-grown talent to pummel their opponents. When it comes to the latter category, Marcus Rashford has been one of United's most exciting players.

Blessed with a great striker's combination of speed and finishing ability, Rashford will be depended on to help bring MU back to Premier League glory. But he's also depended on by England this year to help them regain the level of respectibility that they once routinetly enjoyed on the national stage. England needs consistent scoring and Rashford will be depended upon as a second option next to breakout star Harry Kane and inconsistent finisher Raheem Sterling. '

But word coming out of the England camp says that Rashford suffered "a knock" in training and may miss the first game of the World Cup with the injury. Will England be bitten by the bad luck bug again? If this practice injury is any indication, they may well be!