Edouard Mendy
With Kepa ruled out, Mendy was handed his maiden appearance in the FA Cup by Thomas Tuchel. Chelsea's No.1 goalkeeper had little to do in the opening period as the Blues kept Middlesbrough at bay. The Senegal international wasn't overly troubled after the break either – there were a couple of crosses he palmed away – as the Blues secured their passage to the semi-finals without too much trouble. 7
Cesar Azpilicueta
After his impressive display against Lille in midweek as a wing-back, Azpilicueta was on the right of a back four against Middlesbrough and was equally as dependable.
The Chelsea skipper didn't quite have the same attacking licence as on Wednesday night but defended well and covered Thiago Silva when required. There was one interception in the second half that denied a Middlesbrough break and highlighted the Spaniard's experience and nous. 8
Thiago Silva
The Brazilian's brilliance is that he never appears rushed or uncomfortable. Every touch, every move, every decision comes with authority and it's why Chelsea's defensive record with Silva in their side is so impressive. Middlesbrough didn't have a clear sight of goal and Silva was able to ease through the game as it progressed. 8
Antonio Rudiger
This was yet another opportunity for the German to prove his prowess in a back four and Rudiger did so without too much trouble. He was also able to throw in what is quickly becoming his new trademark; hot stepping towards the byline when the ball is drifting out of play. 7
Malang Sarr
The Frenchman started at left-back ahead of Marcos Alonso and was targeted by Middlesbrough early on. However, Sarr defended well and didn't have a great deal to do in possession as Chelsea were able to work the ball through the home side's midfield rather then needing to progress out wide. 7
Ruben Loftus-Cheek
Deployed alongside Mateo Kovacic in a double six, Loftus-Cheek produced one fine solo run early into the first half but twice lost possession on the edge of the Chelsea box as the Blues looked to play out. On the ball, the England international remains a joy to watch at times and the defensive side to his game is also improving. Yet you doubt he'll ever be a first-team regular under Tuchel. 7
Mateo Kovacic
With Jorginho not in the side or the squad, Kovacic was the senior midfielder for Chelsea and took on that responsibility. He covered plenty of ground to restrict Middlesbrough attacks and was instrumental in the Blues' second goal as it was the Croatian who received possession and drove forward after the Blues broke the Boro press. 7
Hakim Ziyech
Used off the right flank – his favoured role – it was no surprise Ziyech had an impact at the Riverside. He was unfortunate not to get Christian Pulisic through on goal early on with a lovely pass through the Boro defence but then had his moment as he rifled a shot into the far corner from 20 yards.
The Moroccan, who was celebrating his 29th birthday, continued to cause Middlesbrough problems in the second period and delivered two dangerous crosses into the penalty box Chelsea weren't able to make the most of. Ziyech was back to his pre-injury form. 8
Mason Mount
Brought back into the starting XI, Mount was influential in the opening period as he constantly broke forward down the right channel. And it was one of these runs that enabled him to tee up Romelu Lukaku's opener with a fine cross into the six-yard box that the Belgian couldn't miss.
Mount's energy stood out in the second half as he continued to link well with Ziyech, but also dropped into midfield out of possession to offer further protection to Azpilicueta and Silva. The academy graduate was undoubted Chelsea's standout performer at the Riverside. 9
Christian Pulisic
After his excellent goal in midweek against Lille, it was no surprise that Pulisic kept his place in the starting XI ahead of Timo Werner. But the American was quiet in the opening period barring a couple of darts forward with the ball at his feet, although that was perhaps due to a knock sustained when he slipped on the greasy surface.
Pulisic remained on the periphery in the second period as Chelsea focused the majority of their attacks down the right flank, and it wasn't a huge surprise he was replaced with a little more than 25 minutes by Werner. 7
Romelu Lukaku
This was an opportunity for the Belgian to reassert himself in the Chelsea side and he got on the scoresheet with a close-range finish after a Mount cross. Lukaku was on the fringes for the remainder of the first half but looked sharper in the second period and linked well with Ziyech and Mount. But this wasn't a performance to move Lukaku back above Kai Havertz in the pecking order. 7
Chelsea substitutes
N'Golo Kante (for Mateo Kovacic, 68)
Introduced to ensure Chelsea's progression to the semi-finals. Ensured that happened. 6
Timo Werner (for Christian Pulisic, 68)
Given 20 minutes to get on the scoresheet. Had one chance to but was denied. 6
Kenedy (for Hakim Ziyech, 80)
Handed game time for just the second time since returning from his loan spell at Flamengo in January. N/A
Harvey Vale (for Romelu Lukaku 84)
Given a few more first-team minutes. N/A
