Winger Daley, 30, who has made over 50 appearances for Jamaica, spent the final two months of the season on loan at Rotherham, while midfielder Worthington, 28, has made 16 appearances since arriving in January.
Jackson said: "A lot of it is financial. I just need to look ahead to next season.
"I felt it was the right decision because we need a complete change of personnel and a change in mentality."
Jackson added: "We've got 14 players under contract and you have to get players out in order to bring others in. We need to make sure the season we've just had doesn't happen again."
Striker Gareth Evans, centre-back Shane Duff, goalkeepers Lenny Pidgley, Lloyd Saxton and Chris Elliot and Chib Chilaka, Ryan Harrison and Louis Horne have all left the club.
Source: PA
Source: PA