Liverpool manager Arne Slot has revealed that injury played a part in his decision to take Rio Ngumoha off during Saturday's 1-1 Premier League draw with Chelsea.
Calum McFarlane's side ended their six-game Premier League losing run in front of a disgruntled Anfield crowd, who were at least in good spirits when Ryan Gravenberch opened the scoring early doors.
However, Enzo Fernandez's free kick deceived everyone as Chelsea soon equalised in front of the Kop end, and the visitors also had a Cole Palmer strike disallowed for offside.
Boos rang out at full time as Liverpool failed to win a 19th Premier League game this season, and the home crowd also targeted Slot when the head coach withdrew Ngumoha for Alexander Isak midway through the second half.
Seventeen-year-old Ngumoha had provided the assist for Gravenberch's strike and was a lively spark all afternoon, completing four dribbles from five attempts and registering two progressive carries.
Arne Slot: 'Rio Ngumoha was having muscle problems'
Slot's decision to take off Ngumoha was not purely tactical, though, as the Liverpool boss explained in his post-game press conference that the teenager was dealing with muscular issues during the game.
"He was having problems with his muscles and when I asked him he said he was not sure he could continue," Slot replied when quizzed on the Ngumoha-Isak change.
"I knew this would be the reaction because he is such a good player. So often in football, people don't know everything. I am the manager and I need to make decisions."
Ngumoha's assist for Gravenberch was the youngster's third Premier League goal contribution of the season, and one that may still be enough to secure Champions League football for Liverpool this weekend.
The Reds have 59 points, seven more than Bournemouth, eight more than Brentford and nine more than Brighton & Hove Albion, and so their top-five finish will be secured if the Cherries lose to Fulham and the latter two teams also drop points.
Arne Slot was right to take off Rio Ngumoha
Liverpool fans love Ngumoha, and with good reason; the 2008-born prospect departed the Chelsea academy to join the Reds and has rarely let the team down when given a chance this season.
However, the Anfield faithful have not taken so kindly to Cody Gakpo, even though the Dutchman had registered three goal involvements in four Premier League games ahead of the weekend.
Gakpo would have still been supporters' first choice to take off, but the 27-year-old has experience on his side, whereas the fledgling Ngumoha is still growing.
Liverpool cannot repeat the same mistakes that Barcelona made with Ansu Fati, who has experienced a multitude of injury problems after being fast-tracked to the first team, or Gavi, who has played just 317 La Liga minutes this season.
Managers have a duty of care to all players, but especially those who are not even adults yet, and Slot made the right decision to take off Ngumoha - however unpopular it was.