According to Tuttomercatoweb, Boga will be out for 5-6 weeks and will miss at least seven Juventus matches.

It is not only Locatelli. Juventus captain Locatelli has already undergone surgery for a lateral meniscus injury in his right knee. The club said his return will take a considerable amount of time, with a comeback expected around January or February next year. Boga's wait will be shorter. After undergoing examinations at the Juventus Medical Center, he was diagnosed with a moderate injury to the biceps femoris muscle in the back of his left thigh. The club has scheduled a follow-up examination in two weeks to more accurately assess his recovery timeline.
However, it is understood that Boga's absence will likely last around five to six weeks. If this assessment is confirmed, he could return between mid and late October. Juventus will not take risks by rushing him back, especially during a congested fixture period. Given the severity of this type of muscle injury, the team will handle the situation cautiously.
The international break benefits Juventus
At least in terms of scheduling, Spalletti will receive some assistance. After Juventus face Atalanta on September 20, Serie A will pause due to international fixtures, and the Bianconeri will not return to league action until their away match against Cagliari on October 11. This rare extended break means Boga will have nearly three weeks without missing another league match. The Europa League schedule also gives him some breathing room: after Juventus host Nice on September 17, their next European match will not come until the away game against Celta Vigo on October 15. Therefore, the former Sassuolo player is likely to miss only two European matches.
Matches Boga is expected to miss
September 13: Sassuolo vs Juventus - Serie A
September 17: Juventus vs Nice - Europa League
September 20: Juventus vs Atalanta - Serie A
October 11: Cagliari vs Juventus - Serie A
October 15: Celta Vigo vs Juventus - Europa League
October 18: Juventus vs Lazio - Serie A
October 22: Juventus vs Rennes - Europa League (at risk)
Therefore, Boga's most realistic return target could be Lecce vs Juventus on October 25. The final timeline will depend on the results of follow-up examinations over the coming weeks.