Liverpool progressed comfortably on the night, but Slot focused on a decision that troubled him after the final whistle. Speaking openly, the head coach said the game situation forced him away from his original plan to introduce younger players, including the highly rated Nyoni.
Liverpool were expected to rotate heavily and control the tie. They led 2-0 early, but Barnsley pulled a goal back and stayed in the contest longer than anticipated. At 2-1, the match required more control rather than experimentation.
Slot explained his thinking to LFC TV. "I feel really sorry for Trey because maybe it was my mistake," he said. "At 2-1 I thought I had to make the substitutions to win the game instead of giving a young player who is training so hard every single day and is such a big talent the playing time he might deserve."
Instead of turning to Nyoni, Slot brought on experienced options to settle the game. "I thought, 'Let's bring Ryan in first', and that all had to do with us conceding the 2-1," he added. "Usually a game like this should go to three and then maybe more."
Nyoni remains one of the most highly regarded young midfielders at Liverpool. He has trained regularly with the senior squad this season and has made brief appearances in the Premier League, but competitive minutes have been limited.
Liverpool have so far resisted sending him out on loan, preferring to manage his development internally. Slot has previously spoken about Nyoni as a player for the future, not just a squad filler.
This episode highlighted the reality of cup football at the elite level. Managers want to reward young players, but close scorelines demand caution. Slot's honesty showed his belief in Nyoni, even if the opportunity did not come this time.
Liverpool moved into the next round, and Slot's message was clear. Nyoni is trusted, valued and firmly in the club's plans. The challenge now is turning that trust into minutes when the next opportunity arrives.
Chelsea coach Liam Rosenior has said Cole Palmer and Reece James could return to the squad for Saturday's Premier League meeting with Brentford at Stamford Bridge, with final checks to be made after training.
Michael Carrick faces the biggest test of his interim reign when Manchester United take on Manchester City in the Manchester derby at Old Trafford this Saturday.
Liam Rosenior has said Chelsea were "still in this tie" after a dramatic 3-2 defeat to Arsenal in the Carabao Cup semi-final first leg on Wednesday night.
Mikel Arteta made it clear the Carabao Cup semi-final was far from over after Arsenal's 3-2 first-leg win over Chelsea, admitting his side failed to land a decisive blow despite a dominant display.
