The San Diego Padres' historic offseason overhaul may result in an equally drastic fire sale at the trade deadline. All-Star outfielder Justin Upton, who will be a free agent after the season, is among the marquee players the Pads could move.

Rumors find San Diego is already shopping starter James Shields, which means that could just be the beginning. Shields is under contract through 2018 for $65 million and it's likely the Padres will look to deal other high-priced names, including closer Craig Kimbrel, who is owed nearly $30 million through 2017.

While these pitchers are among the better arms in the MLB, the Padres have little use for them given their lucrative contracts as the team sits at 41-49 through the first half of the season. They face fierce competition against the Los Angeles Dodgers and San Francisco Giants in the NL West race as well as the Pittsburgh Pirates and Chicago Cubs in the wild-card race.

Along with Shields and Kimbrel, Upton can help the Padres replenish the loss of young talent they suffered in the offseason.

"Given its place 10 games out in the National League West -- and 7 1/2 back in the Senior Circuit's Wild Card race -- San Diego could deal Upton, arguably the premier free agent-to-be in 2016, in an effort to improve its farm system," writes Dan O'Dowd of MLB.com.

"In the current trade environment -- which is light on available impact bats -- the Padres own an extremely desirable chip. And as for the mindset of a contender? Upton could be the difference between playing or sitting at home in October."

There's also a slim chance the Padres would be able to retain Upton beyond 2015 because their future is uncertain and the 27-year-old is expected to be one of the most expensive free agents this offseason. San Diego set a franchise-record payroll ($108 million) this offseason and it's unlikely they'll go higher with an underachieving team.

Getting value for a top player such as Upton instead of letting him walk in free agency (and getting a draft pick at best) would be a prudent decision for general manager A.J. Preller. So let's take a look at our top three destinations for Upton before the July 31 trade deadline.

3.  Chicago Cubs

The bigger need for Chicago is starting pitching, but given the elite market of top starters, it doesn't appear as if the Cubs will be able to swing a reasonable deal for another arm. It's possible, but the Cubs prefer a young starter with a few years of club control on his deal, which severely narrows their choices.

The main goal is to sign another ace in the offseason because they have the financial flexibility to do so. This gives them the opportunity to improve other aspects of their roster, where they have a glaring need in left field. Upton would be a great fit there.

Since he's a two-month rental he probably won't cost the Cubs an arm and a leg. Previous rumors found they were looking for a left-handed hitting outfielder, but Joel Sherman of the New York Post had an interesting revelation this week.

"There also are executives in the game who think the Cubs might try to make a run at Justin Upton to play left field. Even with Upton a free agent after the season, San Diego would expect significant prospects in exchange. The Cubs - even protecting Bryant, Russell, Jorge Soler and Kyle Schwarber - have significant prospects to deal."

And why wouldn't Upton be interested in re-signing with the Cubs? The team has a bright future and is expected to bolster their rotation in the offseason on top of already being a playoff contender right now.

2.  New York Mets

General manager Sandy Alderson said he'd be "willing to overpay" for a bat before the trade deadline.

Who better than Upton?

Although executives told Jon Heyman of CBS that nothing was close as of last week, rumors find "Padres people were said to be scouting the Mets system, leading to speculation New York could be on Justin Upton."

The Mets rank 28th in the MLB with 310 runs scored and 29th with a .660 OPS. Despite those colossal struggles, New York is 47-42 and two games behind the Washington Nationals for first place in the NL Easst. They've suffered countless injuries this season and absolutely need to add a power hitter with the uncertain status surrounding David Wright's return.

Additionally, Michael Cuddyer has not been performing well on top of dealing with a swelling knee. The Mets' outfield has seriously lacked in the run producing department and the addition of Upton would help facilitate more scoring. First baseman Lucas Duda has not been able to see many pitches from the Mets' opponents because he's really the only significant power threat in their lineup.

Upton has been linked to the Mets in trade rumors and they have both the prospects and financial resources to land him. And again, New York could be an attractive destination for the outfielder beyond 2015 given the big market and promising young future.

Fred Wilpon might even open up his pockets for Upton, who knows.

1.  Kansas City Royals

There's really not much to talk about here. I mentioned this in my column on Monday because the loss of Alex Gordon for two months will undoubtedly affect their standing in the AL Central race. Gordon is both a force on the offensive and defensive side of the ball - an irreplaceable player in a number of aspects.

Upton is just about as close as the Royals can get to filling the void over the next couple of months.

ESPN Insider Jim Bowden said yesterday the Royals are one of the top suitors for Upton, which is not surprising at all. Kansas City can afford to give up a prospect for Upton, who would likely take over in right field for the struggling Alex Rios once Gordon returns from the disabled list. They probably wouldn't be able to sign him long-term in the offseason, but they're serious about a World Series run and Upton would put them over the edge for 2015.

But don't discount other contenders such as the Los Angeles Angels, Tampa Bay Rays, Baltimore Orioles, San Francisco Giants and others who could use a valuable player such as Upton. The Angels were actually close to cracking my top three, but Jerry Dipoto's departure may not have the front office entirely prepared to make such a big move this close to the deadline. Also, they want a left-handed hitter and Cincinnati Reds outfielder Jay Bruce fits the bill there (and he'll also probably be cheaper than Upton).

However, their plethora of pitching prospects and need in left field make a compelling case for their pursuit of Upton.

One thing we know is that potential suitors will be lining up around the block over the next couple of weeks to land the Padres' slugger.