The Champions League round of 16 is well underway, with 12 teams having completed their first-leg fixtures heading into the next round of games on Wednesday.
Paris Saint-Germain, Borussia Dortmund and Olympiakos have treated us to some excellent performances so far, but for every winner, there's been a display of stinking proportions.
Here, we take a look through a trio of individuals who need to up their game when the second-leg schedule arrives.
Mesut Ozil, Arsenal
The euphoria surrounding Mesut Ozil's £42.5 million summer move from Real Madrid has worn off, as has the German playmaker's excellent start to life at the Emirates.
He began the Gunners' tie with Bayern Munich in style, brilliantly winning a penalty with a smart turn inside the box.
Unfortunately for the 25-year-old, that was as good as it got. Ozil lazily patted the spot-kick toward the middle of Manuel Neuer's goal, providing his childhood friend with an easy save.
Although he had no control over Wojciech Szczesny being sent off, Ozil looked lost in the middle of midfield thereafter—an all too familiar sight this season.
Ozil completed just 77 percent of his passes, failed to hit the mark from either of his two crosses and didn't manage a successful dribble all night, as reported by WhoScored.com. He appeared weak when Bayern's numbers swelled, unsure of exactly where he was meant to be playing and generally lacking in confidence.
He can halt the naysayers with a bumper performance in the second leg if he returns to the team by March 11.
Domenico Criscito, Zenit Saint Petersburg
Dortmund's thrilling 4-2 victory against Zenit served up an encounter of relentless speed, constant attacks and plenty of drama. The Russian side played poorly for the most part in front of their own fans, but it was left-back Domenico Criscito's performance that will have Luciano Spalletti most worried.
Criscito fell victim to Dortmund's counterattacking prowess on multiple occasions. He failed to halt Marco Reus for the opening goal of the match, allowing the pacey German to assist Henrikh Mkhitaryan, and he was out of position when Reus added a second moments later.
Although Alexander Anyukov also posted a terrible display in the right-back position, Criscito should be expected to carry out simple duties at the back.
He was overwhelmed by the outright speed of Jurgen Klopp's team, suffering under a lack of cover from Andrei Arshavin before the former Gunners flop was substituted after a quarter of an hour, but he needs to consciously consider his positioning when the next match begins.
Although it is easy to be sucked into the middle, especially with players such as Reus bombing toward the box, Criscito can stop Dortmund's supply from the wing by intelligently sticking to his flank, not leaving huge gaps around the back.
Chris Smalling, Manchester United
From one poor performance to a display that will go down in history as a low for one of Europe's elite clubs.
While the entire Manchester United squad could have featured in this section after their collective failure against Olympiakos—particularly Rio Ferdinand and Tom Cleverley—it's Chris Smalling who needs to improve most.
Occupying the right-back position that appears completely unnatural to a player who possesses poor ball control and a leggy frame, Smalling did a fine impression of a vagabond down the United flank.
Worse than his ability to win zero tackles throughout the match was his inability to keep up with Olympiakos' ambitious front-runners, as the former Fulham defender continued to stand too wide when pressure approached.
That left a huge gap between the struggling player and his centre-backs, who also toiled under constant hassling from the Greek side's centre.
Smalling's distribution remained unambitious throughout, and he continued to play the ball backward, inviting further pressure on the defence. He completed just 79 percent of his passes and, rather oddly, fell over multiple times when under pressure—as depicted by Football Vines:
It's safe to say Smalling's performance was memorable on a dismal night for United. He will need to move into a central position if he is to improve during the second leg, as Smalling's lack of ability on the flank was exposed for all to see once again.