The R&A did not provide a reason for Piercy's withdrawal. He has not played since a third-round 81 at the Travelers Championship which caused him to miss the 54-hole cut, and Piercy had missed three straight cuts prior to that. He finished second last year at both the U.S. Open and WGC-Bridgestone Invitational but has since slid to No. 67 in the world rankings.
Lahiri was a runner-up last month at the Memorial Tournament and will be making his fifth start in The Open, highlighted by a T-30 finish at St. Andrews in 2015.
The R&A also revealed the top of the alternate list, which is determined by world ranking. Tony Finau is now first alternate, followed by James Hahn and Danny Lee.
It's the second stint on the bubble this year for Finau, who skipped his title defense at the Puerto Rico Open because he was first alternate for the WGC-Dell Technologies Match Play, but ultimately did not get into the field.