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Barry Zito, who has struggled in a San Francisco Giants' uniform, still has three years and $57 million left on his contract. There is a good chance that Zito will be boughtout by the Giants, who already have a deep array of starting pitchers

Since the offseason before the 1999 season, when Mike Piazza and Kevin Brown signed by far the two biggest contracts ever at that time, there have been many gigantic contracts, almost none of which worked as a whole.

In the case of many of these large contracts, it is almost as if players are earning money for what they have done in the past, as opposed to what they will bring to the table in the future.

It is unclear whether this tends to happen because players try harder the year before becoming free agents, or if it is simply a result of age and statistical odds catching up to you.

Here are the 10 worst MLB contracts of all-time.

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8 years, $136 million.

Prior to signing with the Cubs, Soriano was coming off of a season in which he became just the fourth player in baseball history to hit 40 homeruns and steal 40 bases in the same season. He had also averaged over 37 homeruns over the previous five seasons.

When the Cubs signed Soriano, who was 30-years-old at the time, to an eight year deal worth $17 million per year, there was little optimism that he could possibly live up to the hype.

In four seasons with Chicago, Soriano has averaged about 26 homeruns, 13 stolen bases and a .271 batting average, not exactly superstar numbers. 

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5 years, $55 million.

There was no reason for the Dodgers to spend this much money on Dreifort.

Dreifort had never won more than 13 games nor had an ERA below 4.00 as a starter in any single season. The Dodgers bought into Dreifort's "stuff" and were afraid of seeing Dreifort pitch well for another team

Throughout Dreifort's big five year contract, he missed two full seasons, starting just 26 games total, to go along with one year in which he provided very mediocre work out of the bullpen. Dreifort has not pitched in the majors since.

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5 years, $65 million.

Chan Ho Park was 28 years old and coming off of back-to-back very solid seasons, in which he averaged 16.5 wins, an ERA of 3.39, and 230 innings pitched.

However, he never found his groove with the Texas Rangers, as he won just 22 total games in a Ranger uniform with a miserable 5.79 ERA, before being traded to the Padres in the middle of the fourth year of the contract.

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5 years, $65 million.

From 1993-1998, Belle was one of the best hitters in the game, averaging 42 homeruns and a batting average over .300.

However, Baltimore may have signed Belle a little late, as he was 32 years old before signing that big contract. Belle played well for the first two seasons, but then suddenly retired.

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3 years, $47 million.

Schmidt's contract is a prime example of a player getting paid more so for what he had done, as opposed to what he still had left in the tank.

Whereas Schmidt was coming off of an All-Star season before signing this contract, he was already 34 years old and clearly past his prime. It was a good thing that the Dodgers didn't sign Schmidt for an even longer deal.

Schmidt battled a shoulder injury throughout his stint with the Dodgers and won just three total games for the Dodgers in three seasons, with an ERA over 6.00

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5 years, $60 million.

Similar to Dreifort, Rowand was a mediocre player coming off of a decent, yet timely season.

Rowand hit .309 with 27 homeruns in 2007, but hit just .267 with 25 homeruns in the two seasons prior.

Through his first three seasons with San Francisco, Rowand has hit .257 with 39 total homeruns.

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7 years, $126 million.

This contract made very little sense at the time and inevitably has not worked out for the Toronto Blue Jays.

Wells had been inconsistent throughout his career before signing the deal, as he had hit over .300 BA twice and over 30 homeruns twice, but with a lot of mediocre seasons mixed in.

Wells was recently traded to the Angeles just a few months ago for catcher Mike Napoli and outfielder Juan Rivera, so now Los Angeles is stuck paying close to $86 million to Wells over the next four seasons

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8 years, $121 million.

Perhaps the most disappointing signing in MLB history, Hampton had been great in Houston and New York prior to signing this contract, but struggled mightily in Colorado, where he had an awful ERA of 5.75 in two seasons with the Rockies

Hampton was traded to Atlanta after two seasons and pitched relatively well for two years before struggling with an elbow injury that he may never recover from. 

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10 years, $275 million.

The biggest problem with this contract, other than the fact that A-Rod is being paid nearly $100 million dollars more than any other player, is that he didn't sign this contract until age 32.

Whereas Rodriguez has been arguably the best player since 1996 and has hit at least 30 homeruns in 13 consecutive seasons, there is little chance that A-Rod, now 35 years old, has more than a few big years left.

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7 years, $126 million.

Zito benefited from being the best pitcher in a weak class of 2007 free agents. From the start, there was little chance of Zito living up to this contract, as he had a decent, but not great, 3.55 ERA in a pitcher-friendly ballpark in Oakland before signing this deal.

Teams were impressed with Zito's 61.8 percent winning percentage with Oakland and six consecutive double digit win seasons, but seemed to ignore Zito's major control issues and far from dominating career.

In four years with San Francisco, Zito has gone 40-57 and there is a good chance that his contract will be boughtout before the start of next season.