The 21-year-old, who joined the Reds in July for £10.5 million, has emerged as an important first-team player for the club; and though he has so far only scored one goal in a Liverpool shirt, he started the first five Premier League games of the season before suffering a minor foot injury against Manchester United.
Borini's loss will be devastating to Liverpool, who, having sold Craig Bellamy, Nathan Eccleston, Dirk Kuyt and allowing Andy Carroll to join West Ham on loan, are left with just one recognized striker, Luis Suarez, in the squad.
Liverpool, who operate in a traditional 4-3-3 formation under new manager Brendan Rodgers, have enjoyed the emergence of youngsters like Raheem Sterling and Suso, players who have helped alleviate the attacker crisis at Anfield. Summer pick-up Oussama Assaidi has also been strong.
But, unless the club applies for permission for an emergency loan or signing, no new strikers can be signed until January; with Borini out, the stores are frighteningly low.
Somebody will have to step up. Fortunately, the Reds have more options than most realize.
Starting with German striker Samed Yeşil. The 18-year-old was brought in from Bayer Leverkusen this summer and has already made his first-team debut for the club. He wouldn't be able to step into the first XI just yet, but could add goalscoring potential to the substitutes bench.
Another option is versatile 21-year-old Spaniard Dani Pacheco. He has never scored in 16 games for the Reds, but his talent is undeniable. He could make the most out of an extended run in the first-team.
A third option is Adam Morgan, a local academy product who is on the fringes of becoming a full-time first-team player. The 18-year-old has already made two Europa League appearances for the club, and, like Yeşil, would add good depth to the bench.
And a fourth option, perhaps the most attractive of all, is to merely let Borini be replaced by committee, with the likes of Assaidi, Joe Cole, Stewart Downing, Sterling, Suarez, and Suso stepping up their own contributions and filling the hole left by Borini together. Everyone does their part.
Whatever the case, Liverpool need to start winning games. With our without Yeşil, Pacheco, or Morgan, that needs to start next Saturday, against Reading.