The sight of Toby Alderweireld on a stretcher wracked the minds of Tottenham supporters who saw their team fight back to a 1-1 draw Saturday against West Brom.

But the point salvaged wasn’t what mattered. The next 48 hours will determine whether Alderweireld suffered a long-term knee injury – and, by extension, if Spurs still have a realistic shot at the Premier League title.

Related: Alderweireld injures leg in Tottenham’s stalemate with West Brom

The 27-year-old’s importance to the Tottenham cause is immeasurable. Not only does he help maintain keep clean sheets, he’s also a launching pad for Tottenham’s attack. Losing Alderweireld means playing Kevin Wimmer or forcing Eric Dier out of a defensive midfield role to play at centre-back.

The consequences are manifold. The trip to the Hawthorns was the first of seven matches in 23 days – a huge run of fixtures that could yet change the winds of Spurs’ season.

He is just one of several starters whom title contenders can’t afford to lose.

Here are four others with a similar umbilical connection to their clubs’ success:

Kevin De Bruyne (Manchester City)

Kevin De Bruyne is Manchester City’s space invader, and it’s no coincidence the club dropped its torrid pace once he suffered a hamstring injury. De Bruyne made a quicker recovery than expected, and showed his qualities as a retriever and a reference point Saturday against Everton. City can’t dominate possession quite as well without the Belgium international in the lineup.

Though he missed a penalty, De Bruyne was involved in the buildup to Nolito’s equaliser. He can recycle possession just as well as he can play a deep pass. Inhabiting a freer role than he did under Manuel Pellegrini, the 25-year-old is clearly a more effective player.

Hector Bellerin (Arsenal)

The best full-back in the Premier League right now is Hector Bellerin. He’s a speed demon who often covers more ground than any other Arsenal player. Bellerin provided the assist for Theo Walcott’s opening goal Saturday against Swansea City, with his overlapping run putting him in a position to cross the ball into Walcott’s path.

Related: Walcott matches last season’s output with brace vs. Swansea

It’s this kind of enterprising play that sets Bellerin apart from the rest. There are so few quality full-backs who are the complete package – a combination of pace, smarts, and crossing ability – but Bellerin certainly is.

A return to Barcelona, where he spent his formative years, may one day happen, but manager Arsene Wenger better hope his 21-year-old can stay healthy in the meantime. Because if Bellerin goes down, there’s only Carl Jenkinson available – and he is coming off his own long-term injury.

Eden Hazard (Chelsea)

After spending the majority of his time on the wing last season, Eden Hazard has finally found space in the middle of the park. Manager Antonio Conte slotted him in a central position for Saturday’s 3-0 win over Leicester City, a tactical decision that gave the Belgian more freedom and a chance to influence play. Here he doesn’t have to worry about tracking back – Nemanja Matic and N’Golo Kante can line up behind him – meaning he can concentrate on scoring goals.

The formation looked more like a 3-4-3, which puts two attacking midfielders in support of Diego Costa. That is clearly aimed at getting the most out of Hazard, Chelsea’s former Player of the Year. A side without him loses a lot of attacking potential, and while Oscar and Victor Moses can fill the role, Hazard is the true gamebreaker.

James Milner (Liverpool)

James Milner is Liverpool’s handyman. He can fill every need. Right now he’s covering Alberto Moreno at left-back, and he’s scoring goals from the penalty spot.

“I’ve trained my whole career to be a full-back and he comes in and makes it look easy,” joked teammate Nathaniel Clyne.

And it’s true. Milner has developed a reputation as a selfless player who can give his team steady performances.

Because Klopp demands lots of running, Milner is able to put his tireless effort to use in Liverpool’s system.

The Reds have enough midfielders already, which is why Milner had little choice but to accept a makeshift role. He is now plugging a hole in the lineup which could be exposed if he goes down with an injury.