Caoimhín Kelleher reprised his role as Liverpool’s Carabao Cup saviour as Jürgen Klopp’s team scraped into round four at the expense of League One Derby. The Republic of Ireland international, who scored Liverpool’s 11th and final penalty in the shootout victory over Chelsea in February, made three saves in another penalty shoo-out after a goalless 90 minutes at Anfield. Kelleher saved from Conor Hourihane, Craig Forsyth and on-loan Everton striker Lewis Dobbin in the shoot-out after the introduction of several big names from the Liverpool bench had failed to break the deadlock in normal time. 18-year-old Stefan Bajcetic and Roberto Firmino failed to convert their penalties for Liverpool, and Darwin Núñez only just did, but Harvey Elliott sealed the holders’ passage with the fifth and final spot-kick. The business intentions of Fenway Sports Group, Liverpool’s owner, was in no way a distraction in the third round tie. Liverpool simply lacked the precision to find a way past Wildsmith, although it was not all one-way traffic and Derby had their opportunities to cause an upset against the holders. Derby had the backing of an impressive 5,600 away support and the defensive structure to contain a young, inexperienced Liverpool forward line. Klopp made 11 changes from the team that beat Tottenham on Sunday and gave five youngsters their full Liverpool debuts – Bobby Clark, son of former Newcastle and Fulham midfielder Lee, 18-year-old Spanish midfielder Bajcetic, forwards Layton Stewart and Melkamu Frauendorf, plus summer signing Calvin Ramsay. Technical quality was on display from all five, with Clark’s nutmegs and midfield runs catching the eye, although their understandable eagerness to impress contributed to a sloppy first-half display by the hosts. Paul Warne’s side looked to hit Liverpool on the counterattack but, despite several determined runs down the right by Nathaniel Mendez-Laing, they did not have an attempt on Kelleher’s goal before the interval. Derby’s best opportunity fell to Eiran Cashin from a Mendez-Laing corner but the centre-half headed high into the Kop. Liverpool, with a more experienced defence and Alex Oxlade-Chamberlain making a rare start in midfield, controlled proceedings without seriously troubling Joe Wildsmith in the visiting goal. Oxlade-Chamberlain was just wide with a volley when Craig Forsyth headed a corner from Kostas Tsimikas into his path on the edge of the area. The roles were reversed when Wildsmith palmed an Oxlade-Chamberlain cross on to the unmarked Tsimikas but with the same result, the left back slicing a volley wide when he should have struck the target at least. Liverpool’s best chance of the first half was created and missed by Stewart. A heavy first touch by Cashin on the edge of the Derby penalty area allowed the 20-year-old to feed Fabio Carvalho in space on the left. Carvalho picked out Stewart with the return cross but, while well-placed in front of goal, the striker was off-balance and skied his shot over. The second half witnessed more attacking intent and quality from both teams, mercifully, and Derby captain Max Bird had a fine chance to break the deadlock when Louie Sibley’s dangerous low cross picked out his run into the Liverpool box. Bird’s first touch struck Nat Phillips but rebounded kindly into his path, inviting a shot that was dragged across Kelleher’s goal and wide. Wildsmith came under sustained pressure thereafter. The Derby goalkeeper reacted sharply to change direction and save a heavily deflected shot from Oxlade-Chamberlain that seemed destined for goal. He then pushed away a curling effort from Carvalho and saw Oxlade-Chamberlain slice over after Frauendorf’s back post headed was only half cleared by Haydon Roberts. Improvement without an end product was not enough to satisfy Klopp and with 24 minutes remaining he summonsed Núñez, Firmino and Elliott from the bench in a bid to confirm Liverpool’s supremacy. The impact of the triple substitution was almost immediate. Firmino and Elliott combined to release Oxlade-Chamberlain behind the Derby defence for the first time and, though he just got his toes to the ball, Wildsmith spread himself well to save. The visiting keeper made an excellent stop with ten minutes left when the prominent Oxlade-Chamberlain floated a superb pass over the Derby rearguard into the run of Elliott. The midfielder attempted to steer a first time effort into the far corner but Wildsmith read the intention to flick the attempt to safety. He also foiled Firmino in the dying moments when the Brazilian headed Ramsay’s inviting cross towards the near corner. Derby also had chances through their substitutes to deliver a cup shock. David McGoldrick sent Lewis Dobbin racing away from Joe Gomez down the right flank. The on-loan Everton striker took his shot first time but sent it bouncing into the arms of Kelleher. McGoldrick should have done better when found unmarked at the back post by a deep cross into the area. His tame header was easily collected by Liverpool’s second choice keeper, however.