Bell, who was in the advanced staged of a return to action following a foot injury sustained during the Pakistan Super League, reported a knee concern following the Second XI Championship game with Lancashire.
"Whilst we are naturally disappointed to lose a player of Ian’s immense talent, one of the positives of 2019 has been the way in which our young, homegrown players have fought in recent weeks."
Paul Farbrace, Sport Director at Warwickshire CCC, said: “It’s extremely frustrating for us, and for Ian, that another injury has happened when he was extremely close to a First Team return.
“Over the last couple of weeks our medical team have been regularly assessing the condition of his left knee, and we have also been supported by sports injury specialists in London. However, the outcome of this has confirmed that Ian will need to have several injections, which rules him out of action for six to eight weeks and effectively ends his season.
“He will now have a three-week period of minimal activity before working closely with our medical and strength and conditioning teams to prepare him for the pre-season programme in 2020.
“Whilst we are naturally disappointed to lose a player of Ian’s immense talent, one of the positives of 2019 has been the way in which our young, homegrown players have fought in recent weeks. They will continue to be given the opportunity to develop and thrive as we continue our Vitality Blast campaign and fight to retain our place in Division One of the Specsavers County Championship.”