They play the sport for the fun, the fame and the money.
Thursday night at Rogers Centre, the Toronto Blue Jays also played it for Ryley James Martin.
Ryley was just 21/2 when he died of leukemia on Wednesday. His family lives in Oshawa, Ont.
Last month at Rogers Centre, Ryley and his parents were invited onto the field before a game where the critically ill young boy won the hearts of both Ricky Romero and J.P. Arencibia with his huge spirit and irrepressible smile.
The two players played with the boy for about 20 minutes, tossed a baseball back and forth and helped him swing a bat. It was a simple deed with ever-lasting affects.
On Thursday, when he arrived at Rogers Centre to prepare for his start that night against the Rays, Romero learned that Ryley had died.
In a heartfelt moment that went largely unnoticed just before Romero delivered the game's first pitch to Ben Zobrist of the Tampa Bay Rays, the Toronto pitcher bent over at the back of the mound and traced the boys initials in the mound with his finger.
For the rest of the game Romero said he drew strength from that simple gesture and it helped him turn in a dominating performance in what was a 3-2 Toronto victory.
"I felt like today, every time I looked at the back of the mound, I kept looking at his initials, just remembered that time we were playing in front of that dugout, just the smile he had," Romero said after the game. "It was definitely something you'll carry with you forever."
Romero pitched ferociously, allowing just one run off three hits over seven quality innings to gain the victory over the American League East-leading Ray, to level his record to 4-4 on the year.
And Arencibia did his part, stoking a two-run homer in the seventh inning that provided Toronto with it's winning margin.
"Pretty ironic, huh?" Romero said. "He [Ryley]was definitely here with us today."
With a group of radio, television and newspaper reporters crowded around him after the game in the Toronto clubhouse, Arencibia held up a large color photograph he has kept of himself with Ryley that was taken last month.
"This is the kid we played for tonight," Arencibia said, holding up the picture. "It kills me because I have nieces and nephews and anytime something like that happens it's tough."
As he was rounding the bases after his big hit, Arencibia said it was a very bitter-sweet moment.
"I shed a few tears after that home run because it was one of those things, it was for him," Arencibia said. "Today's game was for him."