A couple days ago it seemed imminent that the Rangers and Cubs were close to a Matt Garza trade. The Rangers number 2 prospect, Mike Olt, was believed to be the center piece of the package. Their number 7 prospect, Luis Sardinas, was also thought to be included, along with Neil Ramirez and CJ Edwards. The Cubs may also have been adding a second player to the trade. Some thought it might be James Russell. I tend to agree with GW that it very well may have been Alfonso Soriano.
We learned not long after the trade appeared to be nearly complete that there was a snag in the trade talks and it had to do with the medical records for one of the Rangers prospects. Olt, Sardinas and Ramirez each had an injury history that could make a trade difficult. However, Ramirez could have been replaced in the package with relative ease. Even Sardinas could be replaced though it would be more difficult. The player whose injury has been the biggest concern was Mike Olt. He also happened to be the most difficult player to replace.
The Rangers are apparently unwilling to trade Martin Perez (BA #3 prospect, Rangers organization) or Luke Jackson (#6). They're obviously unwilling to trade Jurickson Profar (best prospect in baseball). Martin Perez probably would be enough to go ahead and complete the trade, but he's not available. Luke Jackson's walk rate is a little higher than the Cubs have been targeting in trades since Thoyer took over anyway. It would also probably take more than just Jackson to replace Olt.
That leaves CF Leonys Martin. He's already 25 years old and doesn't offer a whole lot of power. It would take Martin and at least one other highly ranked prospect in the Rangers organization to replace Olt in the trade.
This isn't to say a deal can't done. It's just going to be very difficult for these two teams to match up. The one player who might be substituted for Olt is unavailable and any other prospect they have would have to be included with others.
The Cubs may not want to do that. They could probably trade Garza to another team and get a better prospect than the two for one replacement they're left with in order to complete a trade with the Rangers.
The Rangers are still interested. They've been interested in Garza since he was born and that's not going to change, but I think it's much more likely the Cubs reach a deal with another team. It would seem to be in their best interest to move on and I think that's what they've done.