He sees his swoop for Henchoz as a real coup, with the former Liverpool and Blackburn player's experience vital to the defence.
Jewell said: "A deal has been agreed in principle for Stephane and we hope to complete it within 24 hours.
"He is a quality player and has fitted in really well with the squad since he started training with us last week.
"This will be an important signing for us and I hope there will be three or four more signings before we play Chelsea on August 14.
"I've always promised that the side which starts this season will be stronger than the one which finished the last.
"We've been trying to get the right players in who I think can benefit Wigan in the Premiership, and it's been a case of being patient."
Henchoz trained with Latics at Christopher Park yesterday.
He had spent part of last week with the squad at their Danish training camp, doing well enough in training and one of the friendly matches to earn the offer of a contract.
While never doubting the 30-year-old's ability, Jewell wanted to run a check on his fitness after playing just a limited amount of first team football last season.
All of Jewell's signings to date have been to strengthen the back line – goalkeeper Mike Pollitt, right-backs Pascal Chinbonda and Ryan Taylor, and now Henchoz, bar any late hitches.
But there could still be another defender arriving at the JJB Stadium, although it's unlikely to be Portuguese centre-half Ze Castro who apparantly got cold feet over a transfer from Academica Coimbra.
It's understood Latics have been to watch a defender playing for a club in Holland as their talent net widens.
Jewell isn't just concentrating on the defence, with a central midfielder and a striker high on his priority list.
Spurs' Michael Brown remains a realistic target – Joey Barton isn't.
Up front, there is no end in sight to Nathan Ellington's contract saga, highlighting the need for extra fire-power.
Even if he was to sign a new deal, another striker is needed to provide competition for the Duke, Jason Roberts and David Graham.
With Ellington and Roberts recovering from injury at the moment – a shoulder operation and fractured leg respectively – Jewell had to shuffle the pack in the two Danish friendlies.
Graham was partnered by Lee McCulloch and Gary Teale at various stages of the games, McCulloch hitting the net three times.