The 38-year-old, who lifted the One-Day Cup at Lord's last weekend, is retiring at the end of the season.
Notts says the decision will allow the club to look to the future.
"Chris and I have had a chat. We agree that this a great fit for everyone as we prepare for a T20 campaign", said head coach Peter Moores.
Moores' son, 20-year-old Tom, will keep wicket for Notts as they begin their Twenty20 campaign against Yorkshire at Headingley.
"The thinking is that it allows us to plan ahead for the future, with Chris due to retire in September, yet it enables Chris to pass on his vast experience and knowledge to our players," Peter Moores added.
"He's excited about taking on this new role. It's a good opportunity for him to develop his coaching skills and allows Chris to rest and recharge his batteries after a very busy period.
"He'll be fresh and ready to captain the side when the County Championship matches restart in August."

Plymouth planning officers concluded the plans for Drake's Island should be rejected partly because the little egrets would be disturbed and leave.
Developers Rotolok, who want to build a 25-bed hotel on the uninhabited island, said there was "no problem" with its effect on the birds.
No-one from the council was available for immediate comment.
Drake's Island, which was bought by the Tiverton-based businessman and former Plymouth Argyle chairman Dan McCauley, covers about six acres and contains military barracks and buildings from the Napoleonic era.
Mr McCauley is trying for a third time to get permission to build a Â£10m boutique hotel, bar and restaurant on the island.
Last year, plans submitted by his company Rotolok Holdings for Drake's Island in Plymouth Sound were rejected by city councillors who said more information on the risks to wildlife was needed.
Natural England has now told officers: "The little egrets have selected a roosting and breeding site distant from human activity.
"If the development were to result in disturbance, as we believe is likely even with the proposed mitigation in place, this may result in the complete loss of the breeding colony from this site and communal roost rather than a reduction in numbers of birds present."
Little Egrets
There are thought to be about 700 breeding pairs nationally and it is ranked amber on the RSPB's conservation list, as a rare breeding species.
They first arrived in the UK in 1989, and only started nesting in 1996.
Source: RSPB
Officers recommended refusal to the planning committee on 15 January citing the effect on the egrets and flooding risk.
Mr McCauley's son Aidan said: "I am staggered that after years of close working with council officers they are choosing to ignore the evidence that is before them and turn our proposed investment away.
"My professional team has provided the council with all they need to approve this existing scheme and it is clear that there is no problem with the little egrets, and no need for any off-site mitigation measures to be taken."

Built in the 1970s, the 21 and 23-storey Aston University blocks had been accommodation for generations of students living on campus.
Billy Young, from Demolition Ltd, said it was a complex operation because of the site and need to divert services.
The demolition is part of a ??300m regeneration of the campus. Students were able to watch the event.
He said: "The logistics of working on a live campus, live services - there were a lot of services that had to be diverted in and around the site before the implosion could take place.
"We also had complications of a Victorian water main and gas mains and adjacent footpath that had to monitored on the day in case of any vibration damage."
The Aston Student Village and new research centres will be completed by 2014.
The first phase of the ??215m village project was finished last year which provided more than 1,300  bedrooms for students.
The next stage of the scheme will provide another 1,050 rooms by next yea and will start now Dalton and Lawrence Towers have been brought down.
Notts Outlaws wicketkeeper Chris Read will be part of the club's coaching staff rather than play in this season's T20 Blast, which begins on Friday.
[NEXT_CONCEPT]
A colony of rare birds could thwart a multimillion-pound scheme to redevelop an island in Plymouth Sound.
[NEXT_CONCEPT]
Two university tower blocks have been demolished in a controlled explosion in central Birmingham.