The performances were not as bad as the result suggests, but some things point to the Blues running out of ideas after the first half. After creating - and missing - four gilt-edged chances in the first half, Pochettino's men went ahead to create zero big chances in the second half, despite having 17% more of the ball than they did in the first half. The Blues have all to play for in the second leg, but here is how the Pride of London rates the players' showings:
Dorde Petrovic: 6/10
Petrovic was called upon twice, but he only made one save. The goal that was scored painted many players in a bad light, but none of those players was Petrovic. Moises Caicedo was caught napping and did not track his man in the second-yard box. This is not the first time Caicedo would be in the box and he won't be tracking anyone in a goal conceding situation.
Malo Gusto: 6/10
Gusto's dribbling was quite poor, and he had a hard time dealing with Middlesbrough's left-hand side. His passing was generally good.
Axel Disasi: 7/10
Disasi was OK. He was the only centerback in position when Middlesbrough's Hayden Hackney scored the game-winner on the night. Thiago Silva was caught out - again - and was unable to get back. The Frenchman's passing was very good, and while there was nothing much to do defensively, he missed the one tackle he attempted. He was excellent in the air, but poor in ground duels.
Thiago Silva: 6/10
Silva made one defensive action against Boro, and he was never in a position to make even one clearance. He attempted zero ground duels and zero tackles. This is not at all surprising, as he simply cannot get around the pitch the way he could before. He was so far from play for the Boro goal that he couldn't have influenced proceedings even if he wanted to.
Levi Colwill: 7/10
Yes, Colwill had an error leading to a shot, but he was impeccable defensively for the most part. He completed all seven tackles he attempted, which is impressive. He also won 9/10 ground duels. His passing wasn't as great but he overall had a solid game.
Moises Caicedo: 7/10
Caicedo was caught not tracking his man again for a goal. It also happened against Crystal Palace. He wasn't abysmal, but losing concentration at the wrong time was part of the reason the goal happened. He was otherwise very good defensively.
Enzo Fernandez: 7/10
Fernandez was OK. His passing was good, and his ball retention was superb. He did not get on the ball as much as Pochettino would have liked, considering his passing range, but that was likely by Boro's design. Caicedo using more of the ball than Fernandez is good news for Boro but bad news for Chelsea, though the Ecuador international created a clear cut chance, so maybe not.
Conor Gallagher: 6.5/10
Gallagher was all-action as usual. He contributed well off-the-ball, but not enough in possession. This is an issue because Chelsea had a LOT of the ball.
Noni Madueke: 7/10
Madueke did well to stretch the pitch for the Blues. His dribbling was very good and he contributed well defensively.
Raheem Sterling: 6/10
Sterling was ineffective. He tried many things, but most of the duels he contested were defensive duels as he was unable to impose his game on Boro.
Cole Palmer: 7/10
Palmer impressed at the center forward role. He was impeccable in getting into goal-scoring positions. His anticipation of where the ball was going to land was Erling Haaland-level. Yes, Haaland level. He did miss three clear-cut chances which was ultimately the reason Chelsea did not win, but this was an off day for the youngster, as he is usually a much better finisher.
Mykhailo Mudryk: 6/10
The Chelsea No. 10 did get a shot on target and create a chance. But that was all he did.
Armando Broja: 5/10
Broja tried a few things, but nothing came off. He was emphatically stifled by Boro.
Alfie Gilchrist: N/A
I mean, he played one minute.
Mauricio Pochettino: 2/10
Pochettino started making excuses for his team before the game started. Claiming that fans should not expect a win because of the club's stature and badge is a way of saying fans should expect a difficult game. The issue with his comments is that Chelsea fans don't expect a win against Middlesbrough because of the club's stature, it's because the club has spent a large amount of money on playing personnel and also a manager who is supposed to produce results. Chelsea is a better team than Boro, and should have a better manager than Boro, so Blues fans SHOULD expect to win against them, and saying they should not is an attempt to use the club's form to excuse bad performances. The west London side created only seven shots (no big chances) in the second half, despite having 80% of the ball.