Has Signing Juan Cuadrado Actually Weakened Jose Mourinho's Chelsea Squad?

When Jose Mourinho looked to his bench for his inspiration against Southampton on Sunday, he found it wanting.

Chelsea had been outplayed in the first half and, getting their grip back on the game after the interval, were unfortunate not to score the goal that would have proved the winner.

Diego Costa struck a post, while Cesar Azpilicueta, Eden Hazard and Oscar all found Fraser Forster in inspired form to deny them.

The game ended 1-1, but victory would have papered over the cracks we've seen appear at Stamford Bridge in recent weeks.

Chelsea are lacking the same intensity that saw them break free of the rest of the Premier League earlier in the campaign, and their failure to kill teams off must be a concern for the manager.

Notably, they no longer have substitutes capable of coming on and changing games.

Since Andre Schurrle departed, it's been left for his replacement Juan Cuadrado to make that difference late on.

Only he doesn't. He hasn't even come close.

When Cuadrado signed for £26 million from Fiorentina in January, Mourinho was eager to stress the Colombian would need time to adjust to his new surroundings.

"I don't think the best thing for him is to speak about expectations. He needs time like everyone. He will have his time," explained the Chelsea boss.

Alastair Grant/Associated Press

It was a fair observation, yet now Chelsea's season is reaching the climax, the wisdom of that move should be questioned.

Chelsea banked a big fee for Schurrle that was used to bring in Cuadrado, but where has it left this Chelsea squad?

Cesc Fabregas is struggling for form, as is Oscar. Can Mourinho give either player a rest or make tactical changes to cope? Not right now he can't as Cuadrado is proving ineffective and it's evident his manager doesn't trust him yet.

When Cuadrado appeared after 83 minutes against Saints, it was a move more out of necessity than desire for the manager.

Mourinho had already brought Ramires on for Nemanja Matic and Loic Remy for Oscar, so when Willian picked up an injury, outside of Didier Drogba, there was no other attacking threat.

Rui Vieira/Associated Press

And a threat is hardly what we could call Cuadrado.

The Colombian proceeded to concede possession in key areas, and rather than stimulate the attack, he had a negative impact.

It's been the story of Cuadrado's brief Chelsea career. He's struggling to adjust at a time when his team need him to be putting in performances to ensure their season ends the way it should.

Now isn't the time to be carrying players.

Indeed, given Mourinho is a manager known for being bold and effective with his replacements, Cuadrado's struggles highlight how this Chelsea squad is being pushed to its limit.

Paul Gilham/Getty Images

By allowing Schurrle—and to a lesser degree, Mohamed Salah—to leave in mid-season, Mourinho has limited the resources at his disposal.

Too many key players are out of form, yet he has no alternative other than to persevere. The manager isn't making tactical decisions, simply because he can't. It's about the 11 most capable right now, and without sufficient reserves, he's having to go with those who aren't producing.

Such was Schurrle's dip in form since October, there is an argument to suggest Mourinho felt the same with the German, that he wasn't going to get much from him.

Looking at the stats, however, it reaffirms Schurrle's ability to make an impact at times. He scored three goals in his last month as a Chelsea player and was never afraid of having a shot at goal.

Alex Livesey/Getty Images

Chelsea lacked the presence of a player like Schurrle against Southampton, as they did in that recent away-goals loss to Paris Saint-Germain in the Champions League.

Schurrle gave Mourinho an option, whereas Cuadrado right now does not and Chelsea are weaker for it.

Mourinho is right—we can't judge Cuadrado until next season, yet 2014/15 and lifting the Premier League trophy is the biggest concern right now.

Chelsea are looking like a team on the back foot at a time when they should be sprinting toward the Premier League's finishing line.

Garry Hayes is Bleacher Report's lead Chelsea correspondent. All quotes were obtained firsthand unless otherwise noted. Follow him on Twitter @garryhayes