Wayne Parnell earned over 70 points in each of his previous two matches.
Joshua Cobb scored an unbeaten 146 against Pakistanis in the warm-up game.
"I've been one of England's best seamers in the last few years."
"I am a firm believer that everything happens for a reason."
Pujara has played 103 List-A games in his career and scored 4445 runs at an average of 54.2 with the strike rate of 78 including 11 centuries.
He had notably represented England at the U19 level.
Yorkshire are looking forward to building a team, which remains available throughout the entire domestic season.
The main reason behind Yorkshire’s success in the season was George Hirst’s all-round performances.
Brian Close and the Yorkshire team received heavy criticism for their tactics of time wastage.
Williamson's stint will end after the game against Somerset.