Service manipulation. Plain and simple.
If Vlad Guerrero Jr is called up after three weeks into the 2019 season the Blue Jays would stand to gain another year of playing time and push-off his free agency for another season. I’m not saying that its a bad thing to get an extra year out of what could be a generational talent. However there may be some ways that the talented young rookie does manage break camp with the Blue Jays right away in 2019, and there are a few different ways that it could happen.
Monster spring training: What happens when Vlad Jr shows up to Dunedin in 2019 and absolutely dominates?