Chelsea are yet to be defeated under Thomas Tuchel as they take on Sheffield United in an FA Cup quarter-final this Sunday.Chelsea are riding on the back of a comprehensive victory over two ties against Spanish giants Atletico Madrid as they square off against Premier League minnows Sheffield United in an FA Cup quarter-final on Sunday at Stamford Bridge.Kante & Kovacic ran a midfield show, with Hakim Ziyech lethal on the counter-attack! 👀🔥— Chelsea FC (@ChelseaFC) March 18, 2021The Blues have been undefeated in 13 games since Thomas Tuchel replaced Frank Lampard as manager. The last time Sheffield United kept a cleansheet at Stamford Bridge was 98 years ago and their woeful form this season, which sees them languishing at the bottom of the Premier League table, inspires little confidence.After being in charge of the club for close to five years, Chris Wilder left by mutual consent, leaving Paul Heckingbottom as the interim manager. There is a change in training personnel and it's yet another challenge that the Blades will have to negotiate in what has been a testing season.It certainly doesn't help that Sheffield United's latest outing ended in a 5-0 drubbing at the hands of Leicester City. They will need to come up with something special to put one over on a Chelsea side that has seen off the likes of Tottenham Hotspur, Manchester United, Liverpool, Atletico Madrid and Everton without tasting defeat.Chelsea vs Sheffield United Head-to-HeadIn the last 10 matches between the two sides, Chelsea have the slightest edge over their opponents. Interestingly, Sheffield United have won four of their last ten meetings against Chelsea. Chelsea have won five and one match has ended as a draw.The last time these two sides clashed was in the Premier League in February when Chelsea won the game 2-1.Chelsea form guide: D-W-W-D-WSheffield United form guide: L-L-W-L-LChelsea vs Sheffield United Team NewsChelseaEthan Ampadu won't be allowed special dispensation to face parent club Chelsea in the FA Cup quarter final.Chelsea had allowed Mason Mount and Fikayo Tomori to face them with Derby two seasons ago but it won't happen on Sunday for Sheffield United.— Nizaar Kinsella (@NizaarKinsella) March 18, 2021Thiago Silva and Tammy Abraham will be unavailable until the international break. Andreas Christensen has been out with an illness but there's a chance that he'll recover by Sunday. Jorginho and Mason Mount could not feature against Atletico Madrid in midweek due to an accumulation of yellow cards and are almost certain to start here.Injuries: Thiago Silva, Tammy AbrahamDoubtful: Andreas ChristensenIneligible: NoneSuspensions: NoneSheffield UnitedPhil Jagielka is likely to miss out after his brother tragically passed away midweek. David McGoldrick is the latest addition to the nursing room and he joins Sander Berge, John Egan, Jack O’Connell, Jack Rodwell and Jack Robinson.Ethan Ampadu is ineligible to play against his parent club.Injuries: David McGoldrick, Sander Berge, John Egan, Jack O’Connell, Jack Rodwell and Jack RobinsonDoubtful: NoneIneligible: Ethan AmpaduSuspensions: NoneChelsea vs Sheffield United Predicted LineupsChelsea predicted XI (3-4-2-1): Edouard Mendy; Cesar Azpilicueta, Andreas Christensen, Kurt Zouma; Reece James, Jorginho, Mateo Kovacic, Marcos Alonso; Mason Mount, Christian Pulisic; Olivier GiroudSheffield United Predicted XI (3-5-2): Aaron Ramsdale (GK); Kean Bryan, Chris Basham, Enda Stevens; Max Lowe, John Lundstram, John Fleck, Oliver Norwood, Jayden Bogle; Oliver Burke, Billy SharpeChelsea vs Sheffield United PredictionChelsea have shored up their defense and are unlikely to let the Blades break them. They are high on confidence and Sheffield United are in crisis mode and have been so for a while. Chelsea should win this one comfortably.Prediction: Chelsea 2-0 Sheffield United