The Dutch defender, who joined Liverpool from Bayer Leverkusen in the summer of 2024 for a reported £29.5 million, has endured a frustrating start to life at Anfield.
Frimpong, a key figure in Leverkusen's 2023–24 Bundesliga title win, was brought in to add pace and attacking width on the right flank following Trent Alexander-Arnold's departure to Real Madrid.
However, after recovering from a hamstring strain sustained in the opening-day 4-2 victory over Bournemouth, Frimpong suffered a recurrence during Liverpool's 5-1 Champions League win against Eintracht Frankfurt. According to The Daily Mail, the 24-year-old will not return until after the November international break.
Frimpong's absence adds to Slot's growing injury list ahead of Saturday's Premier League clash with Aston Villa at Anfield. Liverpool, who have lost their last four league matches and sit seven points behind leaders Arsenal, could be without up to 12 players.
Alexander Isak, signed for a British record £125 million from Newcastle United, remains doubtful with a groin issue, while midfielder Ryan Gravenberch is racing to recover from an ankle injury sustained against Manchester United earlier this month. 
Curtis Jones, who limped off in last weekend's 3-2 defeat at Brentford, was left out of the midweek Carabao Cup loss to Crystal Palace.
Goalkeeper Alisson Becker is still recovering from a hamstring injury, with youngsters Jayden Danns and Stefan Bajcetic also sidelined. Giovanni Leoni has been ruled out for the remainder of the season with a ruptured ACL.
For Aston Villa, Harvey Elliott is ineligible to play against his parent club after joining Villa on loan in the summer. Unai Emery may also be without Youri Tielemans and Emi Buendia, who picked up knocks in last weekend's 1-0 win over Manchester City.
With both sides struggling for fitness, Slot admitted this week that Liverpool "must show character and unity" to end their poor domestic run, saying: "Injuries are part of football, but this group have the quality to overcome setbacks."
Liverpool will be desperate for a response at Anfield, and for Frimpong's return to come sooner rather than later.