When free agent starter Jake Arrieta signed with the Phillies this past offseason, the Cubs through Twitter offered up this video of thanks for his time with the club: 

Tuesday night, Arrieta returned for the first time in a Phillies uniform and the Cubs played a truncated version of that on the left-field videoboard. It brought on a nice little moment with the Cubs fans in attendance giving Arrieta a standing ovation and Arrieta coming out of the dugout to salute the fans and opposing dugout. 

Arrieta came to the Cubs in a 2013 trade that is pretty well known as unbelievably lopsided. He came over with reliever Pedro Strop for starter Scott Feldman and catcher Steve Clevenger. 

Arrieta would go 68-31 with a 2.73 ERA, 1.03 WHIP and 8.9 K/9 in his 128 regular-season starts with the Cubs. He won the 2015 Cy Young, was an All-Star, won a Silver Slugger and, of course, won a 2016 World Series ring. He won both of his starts in the World Series, pitching to a 2.38 ERA. 

As such, the exchange of warm feelings comes as no surprise.