Every start Matt Garza makes could be his last for the Cubs, including Wednesday night's outing against the Athletics.

The Cubs are actively shopping Garza in hopes of trading him for two or three top prospects, believing he'll be one of the best available starting pitchers on the market.

"Obviously it hasn't affected him," manager Dale Sveum said. "He's been pitching really, really well."

Garza posted his fourth straight dominant start in a 3-1 victory over the A's, allowing one run on four hits in eight innings with five strikeouts and three walks. He's 3-0 with an 0.90 ERA in those starts.

And the better Garza pitches, the more heated the bidding war becomes.

While some fans might be upset with the idea of trading Garza, restocking the farm system is management's stated priority, and the die has been cast. Getting a good return is crucial, and the Cubs are quickly turning up the heat on the international market.

They reportedly have signed 16-year-old Dominican outfielder Eloy Jimenez for $2.8 million, after netting 16-year-old Venezuelan shortstop Gleyber Torres on Tuesday for $1.7 million. MLB.com, which reported the signings, ranked them first and third, respectively.

Along with the international prospects, the Cubs need a better haul than the one they got from last summer's sell-off. Paul Maholm, Reed Johnson, Ryan Dempster and Geovany Soto netted pitching prospects Arodys Vizcaino, Jaye Chapman, Jake Brigham and Kyle Hendricks and infielder Christian Villanueva.

Here's how they had fared through Tuesday:

•Vizcaino, who was rehabbing from Tommy John surgery at the time of the trade, was ranked as the No. 5 prospect in the Cubs system this spring after coming over from the Braves. But he suffered more elbow soreness in late May and will not pitch for the Cubs in 2013.