Okay...so what does this mean?
Wilson says that the MRI didn't reveal a tear, but did reveal inflammation. Given the size of the Rangers' lead, the chronic nature of hamstring injuries, and the fact that this is the third time Cruz has had this issue this year, I have to think the Rangers want to be conservative in dealing with this, since the last thing you want to do is to push him right now and have him aggravate his hamstring so he won't be available in October.
Arias's return was inevitable, once Cristian Guzman went on the disabled list. This gets the Rangers back to where they have a backup infielder again.
The winner in all of this is primarily Julio Borbon, since it means he's almost certainly going to get to play regularly. The On the other hand, it is going to be harder for Ron Washington to sit Vladimir Guerrero, who looks like he's about 80 years old right now, and could probably use a few days off.
Hopefully, we'll see Brandon Boggs get some playing time against lefties the next couple of weeks, as well. He's out of options after the season, and the Rangers are going to have to make a decision on whether they think he's someone who can provide some value as a 4th or 5th outfielder, particularly given Boggs' history of mashing lefties.
UPDATE -- Boggs is starting in right field today.