"Rachael is obviously an important player for us," Thunder head coach, Trevor Griffin said. "Not just in terms of her cricket skills, but in the way she has led the team this year as well. Losing someone of her ability would impact any team, but our squad is in a great place. I know we'll pull together and be ready to go again on Sunday."
The left-hander is likely to be back in time for the reverse fixture at the WACA in Perth on Tuesday (November 12).
Her replacement, Peterson, the 16-year-old allrounder, was hit on the helmet last week during training and advised a few days rest. She has recovered fully and could be in line to make her debut for the club.
"Kate has come through all the testings," said Griffin. "She's trained very well and is giving everybody in the squad real competition for a place in the starting XI."
Another player who returns to the fold is Rachel Trenaman. The 18-year-old missed the first round of matches in the Women's Big Bash League (WBBL) to focus on her High School Certificate exams. She will replace Phoebe Litchfield, the 16-year-old batting sensation, who has been given time off to to stay home and prepare for her Year 10 exams.
"Sydney Thunder has said all along that Phoebe's education is a priority, and just as we supported Rachel
Despite the changes, Griffin believes that his team - sitting second on the table - has the resources and motivation to take on Scorchers.
"The girls have had a great week, we're in a good place and great shape," he said. "We're looking forward to this next game after a good win over the Hurricanes."