Soriano, a player with a WAR of 0.7 this season, was holding the Cubs back from using younger players and continuing their rebuild. The Yankees, just 2.5 games out of the Wild Card race in the American League, can make much more use of him.
On the season, Soriano has clubbed 17 home runs, driven in 51 and produced a line of .254/.287/.467. Had he played the entire season with the Yankees, his home run and RBI totals would both rank second on the team behind Robinson Cano (21 and 70, respectively).
The upgrade for the Yankees is obvious, but general manager Brian Cashman had his eye on a different outfielder before making the move for Soriano. Joel Sherman of the New York Post reports that Alex Rios of the Chicago White Sox was the primary outfield target for Cashman. Rios had a no-trade clause that prohibited the Sox from dealing him to the Yankees, however.
In comparing the two outfielders, it would appear that Soriano has had the better season given his run production. Rios has the more complete line, however, and the Yankees would likely have preferred the consistency he could have provided the lineup.
He's batting .276/.330/.437 with 12 home runs, 49 RBI, 21 doubles, 21 steals and 51 runs scored. Rios has the higher batting average, on-base percentage, runs total and steals total. He's even struck out 20-less times (69 to 89) in 18 more at-bats than Soriano. Throw in the fact that he's younger (32), a better defender (2.1 dWAR in 2008), less expensive (owed just over $15 million for next two seasons with $13.5 million team option for 2015) and hasn't missed significant time due to injury since 2007, and it's a no-brainer as to why Cashman pegged him as "Plan A."
Rios would have required more of a return as a result, though, and Cashman could have received a ton of flack for dealing away better prospects in what could turn out to be a waste of a season anyway. It remains to be seen if the addition of one outfielder is the difference between turning this Yankees team into a playoff contender, but it's hard to believe that the Yankees are World Series-bound this season.
Cashman was lucky that Soriano was available after missing out on Rios, though. Fans of the team were begging him to make some sort of move to help a sleeping offense, and acquiring the former Yankee (1999-2003) for basically nothing in return was a solid move.
Now it's up to Cashman to find more bargain items to patch his team together for the home stretch. The end goal may be to get younger, but Cashman should just focus on making the team better for now. Acquiring Soriano definitely did that.