Jones is currently with the Wales squad in North America but is expected to arrive in New Zealand on Monday.
Lions head coach Sir Clive Woodward said: "Obviously Simon's discomfort following (Friday's) training session is causing us some concern but we are still hopeful that he will be able to work through it and contend for a Test spot but in the meantime we are adding Ryan Jones to the touring party.
"I offer my congratulations to Ryan, he has had a good season with Wales, he has made an impact on the international scene very quickly and we look forward to him joining us next week."
Scottish star Taylor is struggling with a hamstring problem and has withdrawn from the Lions starting line-up for Saturday's game against New Zealand Maori.
Taylor suffered injury heartache on the 2001 Lions trip to Australia, sustaining a serious knee injury in the opening game against Western Australia and then returning home.