Defensive Coordinator: From what we have been told by sources, Jeff Casteel is absolutely the main target here. There is word that Rodriguez has asked Casteel to join him at Arizona and Casteel asked Rodriguez to give him until the end of the regular season to make a decision.
Casteel makes a good amount of money at West Virginia and would likely easily be Arizona's highest paid coordinator. In addition, he has ties to West Virginia that could make it difficult for him to leave. On the flip side, Dana Holgorson and Casteel supposedly do not have a very good relationship.
If Casteel chooses not to come, it could get interesting here. Despite what Rodriguez may tell the media, we feel confident that he is set on running the 3-3-5. A coordinator like Justin Wilcox could come into play because of his familiarity with running the defense at Boise, but that would not be an easy pull by any means.
In addition, Bruce Tall could be a name to keep an eye on. Tall was the secondary coach at West Virginia under Rodriguez and then moved to the defensive line while at Michigan. He is the current defensive coordinator at Charlotte, but the football program does not start until 2013, thus it would be easy for him to leave.
In reality, the name we are most confident about right now is Casteel, as there are numerous sources that feel he is headed to Arizona.
Defensive backs: Honestly, this seems like an easy one. Rodriguez has said numerous times he is bringing a few coaches that he has worked with in the past and this one seems to be the most obvious. Tony Gibson was the secondary coach at West Virginia from 2001-07 and then followed Rodriguez to Michigan as well.
Gibson has ties to Pittsburgh, where he coaches now, but is very good friends with Rodriguez and has almost certainly been offered a job. We wouldn't be surprised if this is one of the first names announced and don't feel comfortable talking about anybody else because this one seems like a no brainer at this point.
Linebackers: If Casteel gets the job, this will be his position. However, if he does not, there are a few names to keep an eye on.
Ron West is the first, as we know that he has contacted Rodriguez. West was actually an offensive line coach while at Tulane and could join Arizona in that capacity of Frey does not come. West was at Clemson while Rodriguez was there and coached the defensive line as well as linebackers. He has Texas ties, as he has coached at Texas Tech, Baylor, and North Texas in the past. In addition, he would be easy to add to the staff, as he was the linebackers coach for Ron Zook at Illinois.
Former Memphis defensive coordinator Jay Hopson is another possibility. Hopson was removed earlier this season and currently does not have a job. He served as linebackers coach for Rodriguez at Michigan and had great success as Southern Mississippi's defensive coordinator from 2005-07.
Of course, there is always the possibility Tim Kish stays, but that seems to be decreasing.
If Casteel is not defensive coordinator, there will likely be other names to pop up, but for now those three are the ones getting the most buzz.
Defensive Line: This position could go to West or Tall or it could go to an assistant Rodriguez has not worked for before. In fact, it seems somewhat likely that Rodriguez could use this position for a west coast assistant, as he truly does not have a go to guy here.
The coach with the most experience working with Rodriguez as defensive line coach is Bill Kirelawich, but he has been at West Virginia for 31 years and that makes it difficult to see him leaving now.
This position seems to be relatively open considering it is not getting a not of buzz right now and thus there are not many names we are confident in.