Relying on Eden Hazard to provide a creative spark is one thing; leaning on a 20-year-old who has started five Premier League games quite another. Yet this is the reality for Chelsea and it will not sit well with Frank Lampard that stodginess set in so easily when Mason Mount, who has stood out more than most at the start of the post-Hazard era, hobbled off during the early stages of Tuesday’s defeat by Valencia in the Champions League.

Chelsea were ponderous for the rest of an awkward evening and the difficulties they encountered without Mount exposed limitations in this inconsistent side. Although it has been hard to identify the defining qualities of Lampard’s football, the player who looks key to making it work at the moment is a kid. Indeed it is a bitter pill the ankle injury that threatens to keep Mount out against Liverpool on Sunday came after he did exactly what Chelsea’s manager wants from his attacking players, working feverishly to win possession from Francis Coquelin deep in Valencia territory.

The way Mount hassled the former Arsenal midfielder brought to mind the way he scored his first Chelsea goal in the 1-1 draw with Leicester City last month. Then it was Wilfred Ndidi’s turn to be hounded off the ball by Mount, who robbed the midfielder on the edge of the area before driving a low shot past Kasper Schmeichel.

Against Valencia, however, Mount’s energy drew a cynical foul from Coquelin. The England international had started in an inside-left position in a 3-4-2-1 system, a conduit between Tammy Abraham in attack and Mateo Kovacic and Jorginho in midfield, and Chelsea’s fizz ebbed away when he went off. Mount’s replacement, Pedro, was unable to link play as effectively.

Encouragingly Mount, at his best in a central role but capable of drifting inside from the left, was not on crutches after the Valencia game. A scan showed no ligament damage and he was working hard away from the main group at Chelsea’s training ground on Thursday. Two members of the coaching staff, Joe Edwards and Chris Jones, were watching as Mount completed shuttle run after shuttle run. He was moving well and Lampard, keen to show support, soon joined them.

There remains a chance that Mount, who has three goals in the league, could play against Liverpool. Yet while Lampard said that Mount could strap up his ankle and play through the pain, Chelsea’s manager does not gamble unnecessarily. N’Golo Kanté and Antonio Rüdiger, who is out with a groin strain, have been given time to return from respective ankle and knee injuries. Kanté must prove he is approaching top speed before being restored to the side.

All of which means the likeliest scenario is Mount sitting this one out, leaving Lampard to find a way of beating the Premier League leaders without a player who has already become crucial to Chelsea.

It is probably not worth dwelling on Lampard’s Derby side struggling whenever they were without Mount, who excelled during his loan with the Championship club last season. After all, Chelsea have a squad packed with established internationals.

Equally it is difficult to ignore Chelsea’s 11 league goals all being scored by academy graduates this season, raising questions about the senior players. “I’m not concerned with age,” Lampard said. “We have a squad. All Mason has done is set a really high level. If he’s not playing other players need to contribute and we’ll need goals from all over the team, and they’ll come.”

However, there is little to suggest that Pedro and Willian were simply waiting for Hazard to join Real Madrid before stepping out of the Belgian’s shadow. Pedro scored eight goals in the league last season. Willian scored three.

Both have been important for Chelsea, and they do have weapons, Pedro with his scuttling running and eye for goal, Willian with his speedy dribbling and dangerous set pieces. Yet they are not known for dominating big games and although Lampard is happy with Willian’s recent displays, the Brazilian hardly distinguished himself by arguing with Ross Barkley before the midfielder clipped the bar with that late penalty against Valencia.

Barkley is another who needs to produce more – the England international scored three times last season – and Chelsea are having to be patient with Christian Pulisic, the £58m signing from Borussia Dortmund.

The American winger was an unused substitute against Wolves and Valencia, though there is a case to pit his pace against Liverpool’s right-back, Trent Alexander-Arnold.

At 20 Pulisic has room to become as vital as Mount. Bigger questions hover over those with more miles on the clock, which is why it remains hard to make definitive judgments about Lampard’s start. He inherited an uneven squad and is hamstrung by a transfer embargo.

Rejuvenation has come from within. Abraham has scored seven goals and there was good news this week when Callum Hudson-Odoi, who will continue his comeback from an achilles injury with the under-23s on Saturday, signed a new five year-deal. Hudson-Odoi, a winger with thrilling potential, and Reece James, a promising young defender, will be involved against Grimsby Town in the Carabao Cup on Wednesday.

Ruben Loftus-Cheek is also working his way back from an achilles injury and it is only when Lampard has enough youthful energy and imagination at his disposal that the reliance on Mount will lessen. Chelsea will suffer further setbacks until then and Liverpool, who have spent four years learning Jürgen Klopp’s football, are primed to capitalise on the developmental weaknesses in a team dreaming of a bright future but fearful of what tomorrow holds.