MLS has posted a nice roster summary page that fills out the final details of our roster. The main thing it answers is that we only have 6 international slots after our offseason trades. This has led to the Rapids loaning Dennis Castillo out as he would be our seventh international player. There's been no announcement beyond his status on that page as to where he's going, but I would assume Charlotte. Apparently he hasn't left yet though, as Daniel Boniface tweeted that he was at practice yesterday.
Also over the weekend the Rapids announced they signed first round draft pick Sam Hamilton. The only unsigned player at practice yesterday according to Boniface was draftee Jamie Siaj who's still recovering from his injury. If/when he signs he would take one of the two remaining reserve roster spots. There was also rumors late last week of defender Mike da Fonte of the Sacramento Republic moving to the Rapids. He wasn't with the Republic this past weekend but he's not yet in Colorado. If accurate he would presumably fill the other remaining reserve roster spot.
That leaves the two senior roster spots to fill. With no international slot at the moment they would have to be filled with domestic players, but that could be changed with a trade (or if Sjoberg or Badji get their rumored green cards). The most likely way of filling them right now then is a trade within the league. There are no rumors of trades at the moment though.
Coverage will be a bit lighter for the next couple of weeks. More details after that but I'll keep the blog updated as best I can with any news and results.