Two of the top pitchers of their time will be inducted into the Baseball Hall of Fame this Sunday in Roy Halladay and Mariano Rivera. And a special artifact will forever commemorate their connection in Cooperstown.

Halladay, the late Toronto Blue Jays and Philadelphia Phillies ace, famously approached Rivera, the longtime New York Yankees closer, at the 2008 MLB All-Star Game in order to ask him how he threw his signature cutter. In response, Rivera used a pen to trace his grip onto the ball, then gifted it to Halladay.

The same ball stayed with Halladay for the remainder of his MLB career, as 12up's Scott Rogust noted, and has since been donated to the Hall of Fame by the pitcher's widow, Brandy.

Rivera, 49, spent all 17 seasons of his MLB career with the Yankees, retiring as baseball's all-time leader in saves and games finished. The 13-time All-Star finished in the top three top-three for the the AL Cy Young award four times, and helped New York win five World Series between 1995 and 2013, claiming World Series MVP honors in 1999.

Halladay split his career between the Blue Jays (1998-2009) and Phillies (2010-2013), garnering eight All-Star honors and two Cy Young awards. Just the fifth pitcher in MLB history to throw multiple no-hitters in the same calendar year, he pitched the 20th perfect game of all time as a member of the 2010 Phillies and twice led MLB in victories. Halladay died at the age of 40 in November 2017 when his plane crashed off the coast of Florida, but he's since had his number retired by the Blue Jays and been enshrined on the Phillies' Wall of Fame.