As I mentioned yesterday, Lopez has joined the Cubs roster this weekend. The Cubs outrighted Luis Valbuena to AAA Iowa. Valbuena was out of options and had to clear waivers before he could be sent down.
The Cubs have done a good job of timing their moves to make it difficult for other teams to claim players. They have only lost Jeff Bianchi and John Gaub through the waiver process so far, although Sonnanstine did clear but then exercised his right to become a free agent. Of course, one could always argue that nobody wants the guys the Cubs are waiving. From a Cubs perspective, they have to be happy that they have managed to keep some usable pieces such as Manny Corpas, Frankie De La Cruz, and Adrian Cardenas.
Lopez becomes the long reliever and adds the veteran that manager Dale Sveum was looking for in the bullpen. He also gives the Cubs an immediate option should they need a last minute emergency starter.
For Iowa, it means another big bat. Valbuena has feasted on AAA pitching but has had trouble making the adjustment to major league pitching. While he's not great defensively, he may get some time at SS so that both he and Cardenas get playing time. He'll also see some time when Iowa uses the DH.
The Cubs have now safely stashed 3 LH hitting second baseman -- two at Iowa and one on the bench. It gives them flexibility for a deal down the road as well as having some options behind starter Darwin Barney.