"It is a business, right?" Arenado said.
"I've been traded once. I think that shocked a lot of people at that time," he added. "I guess it doesn't surprise me anymore what happens in this game."
Arenado made the comments from the All-Star festivities in Seattle, where he is the lone Cardinals player in this year's Midsummer Classic.
The typically successful Cardinals headed into the All-Star break sitting in the basement of the National League Central, a dismal 11.5 games behind the first-place Cincinnati Reds and 14 games under .500.
"We're all surprised with what's going on here," Arenado said. "It's been a tough first half. Nobody wants this. We know St. Louis fans aren't happy about it and we completely understand. If they're not happy about it, then you can imagine where we're at."
"It would still be surprising seeing certain things happen," Arenado said. "But I understand that there's certain things that probably should."
Arenado earned his eighth career nod as a starter for the National League All-Star team. In 86 games this season, he's batting .283 with 19 home runs and 62 RBIs.