Born in Livorno, Borghini was a youth exponent from Empoli. Here he played 55 matches and scoring 2 goals for their U-19 team. On 31 January 2015 he received his first call-up on the bench in a match against Roma in Serie A, however he remained an unused substitute.
Loan to Tuttocuoio
On 12 July 2016, Borghini was signed by Serie C side Tuttucuoio on a season-long loan deal. On 31 July, Borghini made his debut for Tuttocuoio in a 3–2 away defeat, after extra-time, against Casertana in the first round of Coppa Italia, he played the entire match. On 28 August he made his Serie C debut for Tuttocuoio in a 2–2 away draw against Prato, he played the entire match. On 31 October, Borghini scored his first professional goal in the 93rd minute of a 2–1 away win over Pontedera. On 21 May he was send off with a double yellow card in the 90th minute of a 2–2 home draw against Prato. Borghini ended his loan to Tuttocuoio with 16 appearances, including 14 as a starter, and 1 assist, but the team was relegated in Serie D.
On 17 July 2017, Borghini was signed by Serie C club Gavorrano on a season-long loan deal. On 27 August he made his Serie C debut for Gavorrano as a substitute replacing Manuele Malotti in the 77th minute of a 2–1 away defeat against Livorno. On 24 September he played his first match as a starter for Gavorrano, a 1–0 away defeat against Prato. On 8 November, Borghini played his first entire match for Gavorrano, a 0–0 home draw against Arezzo. Borghini ended his season-long loan to Gavorrano with 27 appearances, but Gavorrano was relegated in Serie D.
Arezzo
On 30 August 2018, Borghini joined to Serie C club Arezzo with an undisclosed fee. On 25 September he made his debut as a substitute replacing Carlo Pelagatti in the 60th minute of a 0–0 away draw against Pisa. On 11 November, Borghini played his first entire match for Arezzo, a 2–2 away draw against Novara. On 27 April 2019 he scored his first goal for the club in the 49th minute of a 2–0 home win over Gozzano. One week later, on 4 May he scored the second goal in the third minute of a 3–0 away win over Pistoiese. On 4 August 2019, Borghini played his first match in Coppa Italia for Arezzo, a 1–0 home win over Turris in the first round, and one week later he scored his first goal in this competition in the 10th minute of a 4–3 away defeat against Crotone in the second round.