If your toddler doesn't want to do whatever they're supposed to be doing right now, just wait half a minute. No matter how severe the objection, how much kicking and screaming, they're just as likely to do a complete 180 and decide that they really want to be doing that a minute later. The playground on the way to soccer always looks more fun than soccer because it's right there and soccer is somewhere off in the unknown future.
The fervency of opinions at this age are matched only by their brevity. "No" is very often about him declaring he has agency more than about the specific decision. I've found that firm but gentle patience works best when handling his protests. Sometimes a quick distraction is all that's needed to make him forget what he was upset about (Ooh! Look! A butterfly!) and get him back on track to what you were on your way to do. What rarely works is trying to convince him that he actually wants the thing he just said "No" to. Honestly, that doesn't always work with adults either.
He does love soccer right now. They're finally starting to have the kids pair off for a 4 goal match-up and he's gone 3-0 and 3-1 the last two times. Admittedly there's a bit of hand ball and some red card worthy football tackles, but his physicality and competitive spirit is impressive. I never really participated much in organized sports until middle school, and even then not that much. I'd love to give him the encouragement to stick with something long enough to learn the joy of mastering a skill over time, but I don't ever want it to become something he does because of me and not because he likes it.