I'll assume the patch was cut from a 'game-worn' jersey from the 2006 Futures Game in Pittsburgh - since I cannot immediately associate the colors on the patch card to a Milwaukee Brewers uniform.
Other reasons include, Gallardo was on the World team for the Futures Game, Topps has printed a Gallardo jersey insert card from the Futures Game before [in 2006 Bowman Draft] - it states on the back of this card:
"The relic contained in this card does not come from specific game, event or season."
I picked up the card for $5, which is probably too much, but I realize $5 can't get me an 2009 Upper Deck Ultimate jumbo patch card - and regardless of perceived value of the card, Gallardo is a rising star who is the ace of the Brewers' pitching staff.
For my collection, a card with a small patch swatch is OK - I do like the novelty of being able to see a little bit of the jersey from where the patch was cut from. Seeing some separation between the actual patch and jersey material gives a patch card some character.
It is disappointing when a patch card only has a one-color patch piece covering the entire window where the 'game-used' jersey / material is visible - the purported patch card becomes like another a plain jersey swatch card.