Juve head coach Maurizio Sarri wants Lukaku to be his main centre-forward heading into the 2019-20 campaign, with Cristiano Ronaldo being deployed on the left flank and Federico Bernardeschi on the right.
That means that Dybala would have to settle for a rotation role similar to the one he had under former coach Massimiliano Allegri that saw his playing time reduced following Ronaldo's blockbuster arrival from Real Madrid.
Indeed, Ronaldo is capable of playing centrally and Mario Mandzukic would seemingly be ahead of Dybala in the pecking order in terms of a direct replacement for Lukaku, while Douglas Costa and Juan Cuadrado offer alternative options out wide.
There is also the presence of Gonzalo Higuain, although Juve are looking to move on the 31-year-old should a suitable offer arrive.
As revealed by Goal, Juve are ready to listen to offers for Dybala, while the club's vice-predicent Pavel Nedved has confirmed there have been "some proposals", with Tottenham having also been strongly linked.
As for Inter, who have been linked with Lukaku throughout the summer and made no secret of their desire to take him to San Siro, they would have to resort to Plan B, should the former Everton striker not end up joining them.
Antonio Conte currently only has Lautaro Martinez as a recognised striker, with Mauro Icardi having been told he has no future with the Serie A club and having not taken part in any of their pre-season preparations to date.
Edin Dzeko is another who is on Inter's wanted list although, like Lukaku, there are complications in terms of negotiations, with Roma demanding €20m (£18m/$22m) or alternatively a transfer that would see Icardi swapped for the former Manchester City man, with the Nerazzurri expecting €30m (£28m/$33m) as part of that deal.
The latter scenario would free up the necessary funds for Inter to go for Paris Saint-Germain forward Edinson Cavani, with the Ligue 1 champions demanding as much as €50m (£46m/$56m), and leave Conte with the two striker purchases he has been craving.
As it stands, Dybala is ultimately proving key in a complicated transfer merry-go-round that could trigger as many as four transfers relating to Italy's top flight.
Should the Argentine be open to a move to Old Trafford, and Ole Gunnar Solskjaer and executive vice-chairman Ed Woodward also agree to a deal, that would leave the path clear for Lukaku to make the switch to join Sarri's Juve.
United, meanwhile, continue to chase Leicester City centre-back Harry Maguire, while they have also been linked with midfielders Bruno Fernandes and Sergej Milinkovic-Savic.
Paul Pogba is looking increasingly likely to stay at the club, meanwhile, with Real Madrid's hopes of landing the Frenchman fading amid the Red Devils' reluctance to open negotiations amid fears they won't have enough time to sign a suitable replacement.
Lukaku is, however, one member of the United squad that looks almost certain to leave and the Belgian, who has played no part in pre-season, teased a possible exit as he posed for a photo with agent Federico Pastorello and captioned the image "soon to be continued".