The Portugal international was informed by the Court of Arbitration for Sport earlier this week that FIFA's decision to ban him from playing until January 1 still stands.
Silva's predicament relates to delayed paperwork when joining the Foxes from Sporting Lisbon in the summer, with the finishing touches not being completed until 14 seconds after the deadline-day cut-off point.
"It is difficult for Adrien because he just has training sessions all the time, without an objective and without the possibility to play," he told reporters.
"It is a pity because we have a good player and no possibility to put him on the pitch but it will be a good thing for the squad to have Adrien with us. We need to prepare Adrien for January.
"It will give us other opportunities for the team, it is important to have a lot of players available. We sometimes play every three days, or every two, so we need a lot of players with quality for all these games. But there is a possibility for other players [to impress in Silva's absence]."
Silva's last competitive action came for Sporting against Victoria de Guimaraes in the Portuguese top flight on August 19.