Our rules do not allow for Suspended players to be placed on IR, unless that has changed, although I am not finding anything that shows this being done...this was asked in the past, but only one response from Mutts:
http://www.predsff.com/forums/showth...ight=suspended
Here is rule:
Each team has a maximum of two (2) injured reserve slots. For a player to be put on IR he must be listed as Questionable, Doubtful or Out on any NFL.com weekly injury reports. Any player placed on IR must remain on IR for a minimum of 4 weeks. By the start of the next rookie draft, each franchise must clear IR and have no more than sixteen players on their roster. Once a player is placed on IR, the club can pick up another player but they must go through the free agent channel as with any other pick up.
Jackson is not listed on this weeks injury report - so looks like you need to free up some room elsewhere