Billy Beane had to make this trade.

The Oakland A's might not be in this position a year from now, let alone three years or five or 10. The A's have been the best team in baseball in this season of parity, a season without a clear title favorite. But the A's had a flaw -- or the potential for one -- and Beane couldn't afford to let his team whither as the rotation slowly disintegrated.

So give him credit for having the guts to trade 20-year-old Double-A shortstop Addison Russell and Class A outfielder Billy McKinney to the Cubs for two-fifths of a championship rotation in Jeff Samardzija and Jason Hammel. Those two will join Scott Kazmir and Sonny Gray and whoever holds down the fifth spot to now give the A's maybe the best rotation in the American League to go with what has been the league's most potent offense.

The rotation leads the AL in ERA, a surprising development given the season-ending injuries to Jarrod Parker and A.J. Griffin in spring training, but has been progressively worse each month since a blistering April. Given that Gray and Jesse Chavez have never pitched a full season in a big league rotation and Kazmir hasn't pitched more than 158 innings since 2008, there was also concern about the rotation wearing down.

Now Beane has added two guys currently sporting ERAs under 3.00 with excellent peripherals. Yes, trading a cheap, team-controlled potential star such as Russell, a top-10 prospect entering the season, is antithetical to what small-market teams with limited resources normally do, but consider that Beane might not be able to keep this core together much longer.

Josh Donaldson will start to get expensive next year, and Brandon Moss will be due for a big raise. Jed Lowrie will a free agent after this season, and perhaps most problematic, Yoenis Cespedes will be a free agent after the 2015 season.

So, yes, I love the move to go for it now. Interestingly, I had proposed on Twitter on Thursday night the idea of trading Russell for David Price. Reaction was split, though I'd say a small majority favored the A's keeping Russell.

Such is the world we live in, where prospects are coveted like gold. Russell will likely develop into a nice player; when I talked to him in spring training he came across as a quiet but confident kid with a good head on his shoulders. Donaldson praised not just Russell's talent but also his work ethic. It certainly wasn't easy for Beane to trade his shortstop of the future.

But Beane is eyeing his own gold -- the kind you put in a World Series ring. And this trade clearly makes the A's the World Series favorite.