Juventus have won Serie A five years running and stand as the clear favorites going into the 2016/17 season. With the summer transfer window already underway and the season's start rapidly approaching, Roma, Napoli, Milan and Inter have a lot of work to catch the champs.

Holding onto star players is probably the biggest priority for most teams in Serie A, but beyond that, it's going to take intelligent maneuvering in the transfer market to challenge Juventus. Let's take a look at what business these teams need to get done before the transfer deadline passes and the rosters are frozen until January.

Juventus

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Juve have already completed some major deals this window, activating Miralem Pjanic's release clause to snatch him from rivals Roma, reinforcing the fullback/wingback position with Barcelona's Dani Alves on a free, and bringing in former Roma defender Mehdi Benatia from Bayern on loan to bolster the backline.

Paul Pogba's future is the biggest pending question for Juventus, but whether or not he stays, they'll still need to sign a defensive midfielder and at least one attacker to replace the departed Alvaro Morata. Should Pogba leave, two top quality central midfielders will likely be on Giuseppe Marotta's shopping list. So no matter what, The Old Lady still have work to do, especially since they're also dreaming of Champions League glory.

Napoli

Gonzalo Higuain scored goals like they were going out of style last year, but Napoli still couldn't take advantage of Juventus' awful start in the league, eventually finishing second behind the champs. This year, they face a herculean task holding onto the Argentine, and they need to strengthen in some key positions to mount a real title challenge.

Antonio Conte's favorite ultra-versatile mighty mite Emmanuele Giaccherini has already signed on, but Napoli need reinforcement at the fullback position as well as in midfield. Axel Witsel has been constantly linked to the Partenopei as the answer for their midfield woes, but negotiations for him (like many before) have stalled due to Napoli's complex image rights demands. If they can hold onto Higuain, the rumored arrival of Davide Santon from Inter Milan goes through and they can get a quality center-midfielder, Napoli will at least feel confident of mounting a decent title challenge against Juventus.

Roma

Roma just lost their best player to Juventus and their starting left back to Barcelona, but they've got a strong core in place for Luciano Spalletti. Kevin Strootman is back from injury, and for the time being, i Lupi have managed to fight off interest in tenacious midfielder Radja Nainggolan.

After Antonio Rudiger's cruciate ligament injury they wisely added center-backs Nacho from Real Madrid and Juan Jesus from Inter, but they're in desperate need of a right fullback and a midfielder or two to handle the creative vacuum left by Miralem Pjanic's departure. Until they can properly replace him (no small task), Roma supporters won't rest easy.

Inter Milan

After slumping to fourth in Serie A last season, Inter Milan are in need ... well they're in need of a lot. Despite having already completed the signings of creative midfielder Ever Banega and left back Caner Erkin on free transfers, Roberto Mancini's team is unbalanced at best, and they need strengthening in a couple key areas.

Chief amongst the recently bought club's worries is holding onto their captain and talisman, striker Mauro Icardi. They also need a winger to play across from Croatian Ivan Perisic, a quality center-back to play alongside Jeison Murillo, and could use at least one more attacking player to round out the summer's work. So they need a lot.

AC Milan

AC Milan probably have the biggest task of any of these sides on their hands. Chief amongst their transfer worries is the club itself, and for weeks going on months, officials have been locked in negotiations to sell Italy's most successful European side to a group of Chinese investors. As the deal approaches reality, Milan's transfer strategy should fall further into place. If they do get sold, not being a slave to Silvio Berlusconi's ever-changing personal finances will be a nice change.

A complete squad overhaul wouldn't hurt in this case, but as it stands, at the very least, Milan need a quality center-back to pair with Alessio Romagnoli, a quality creative midfielder, and, with striker Carlos Bacca likely on his way out, at least one attacker to help replace the goals that leave with him. New signing Gianluca Lapadula, recently arrived from Pescara, is, in theory, a solid addition, but he's 26 years old, unproven in Serie A, and Milan supporters will surely expect to see at least one more player capable of firing in the goals arrive before the end of August comes and goes. And all that would just keep them in the same ballpark they were in a year ago, when they finished seventh.

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