Arne Slot is sweating on the extent of Hugo Ekitike's injury after the Liverpool striker missed Sunday's thrilling 2-2 draw against Fulham.
Ekitike had an MRI scan that revealed a minor issue and forced Slot to leave out the 23-year-old at Craven Cottage.
Without Ekitike and with fellow forward Alexander Isak also injured and Mohamed Salah on Africa Cup of Nations duty with Egypt, Liverpool spluttered through a disjointed display in west London.
Harry Wilson put Fulham ahead in the first half before Florian Wirtz netted after the break with a controversial goal that was initially disallowed for offside before VAR overturned the incredibly tight decision.
Cody Gakpo's goal in the fourth minute of stoppage-time looked to have earned Liverpool a valuable victory in the race to qualify for the Champions League.
But Fulham's Harrison Reed lashed home from 30 yards in the 97th minute to force Liverpool to settle for a second successive draw.
The toothless Reds failed to register a shot on target in the first half without Ekitike, who is their top scorer this season with 11, more than double the tally of second-placed Dominik Szoboszlai.
"He (Ekitike) felt something during the training session so he went for an MRI scan," Slot said. "We got the result when we were flying so we were hoping it was just DOMS (delayed-onset muscle soreness)."
Slot added his new signings were still getting used to the physical demands of the intense schedule of a top English team.
"He has to play 80 or 90 minutes every single game, for the first time in his life at Premier League level, for the first time without a winter break, for the first time at Champions League level," Slot explained.
"Not a surprise that he then gets bit tired. Unfortunately we saw a little bit more (on the scan) and you cannot take a risk.
"Florian (Wirtz) is also for the first time experiencing this programme, and if I don't have that many players I would like the ones that I do have available and playing as many minutes as possible."
Liverpool are now unbeaten in nine games in all competitions ahead of their trip to Premier League leaders Arsenal on Thursday.
But Slot was frustrated that his side let the lead slip in a season marred by uncharacteristic meltdowns from the champions.
"If you're not part of Liverpool or you don't follow us every game, you'd think we win it," Slot said.
"But unfortunately I'm experiencing this for months now. The only chance they got in the first half led to a goal. That's one thing we usually see with us."