Captain Cook admitted he called 115-Test veteran Bell to confirm the 33-year-old had been dropped from England’s four-Test South Africa trip.
He believes Bell can reinvigorate and extend his Test career by taking time out of the spotlight, as the England captain managed after missing this year’s World Cup.
Cook also tipped Alex Hales to have first-refusal on the fight to become his long-term opening partner when the Test series against the Proteas starts on Boxing Day.
“I sat in on that selection meeting, it was a fairly long selection meeting,” said Cook of the deliberations over dropping Bell.
“You will miss his experience, but I think he would be the first to admit he hasn’t quite scored the runs he would have liked in the last two years.
“It’s a weird thing, but sometimes missing a tour or missing some time might do him the world of good.
“I think he’s been on every tour in one sense since 2000, so a bit of time away from the game might do him the world of good.
“I only look at the World Cup squad a year ago and how gutting it was for me to miss that.
“But two months out of the firing line, some time to be at home, it gave me a new level of understanding and a new lease of life.
“I have spoken to Ian, and yes, it was an interesting phone call. All I got from it is how desperate he is to come back. It’s a great encouragement that a player of his class who has done so much is still hungry to come back at the age of 33 and still show what he can do all over again.
“He wants to prove himself again, he’s up for that challenge, and it’s exciting to have a fully-refreshed Ian back in the selection.”
Steven Finn could yet join England’s South Africa tour as he continues his recovery from foot trouble.
Cook backed Finn to join the tour “sooner rather than later”, but insisted the first Test would come too soon for the 26-year-old.
Hales, Yorkshire’s Gary Ballance and Jonny Bairstow, and Nick Compton will all fight for Test spots on the winter tour, with Cook expecting England’s youngsters to make quick progress.
“From where Trevor (Bayliss) spoke at the end of Pakistan he’ll certainly be given the first opportunity at it,” said Cook of Hales’s chances of a top-order berth.
“You can’t guarantee anyone a Test place when you’re sitting in a Heathrow hotel, but he’s got a great opportunity and we know he can be very destructive.
“In the last six months in international cricket he has experienced a great deal. So it’s a great chance for him now.
“Nick (Compton) has got a great opportunity now too, we haven’t quite got a settled top seven.
“With Gary (Ballance) coming back, and Nick coming back they’ve had a taste of it before so there’s a real opportunity for people to stake their claim.”