"Why would the Red Sox give Fitts, who wasn’t even in major league spring training, the chance to join the major league team and pitch against the defending World Series champions? The answer has a little to do with logistics and a lot to do with how much Fitts impressed Red Sox brass in his first spring with the club. According to farm director Brian Abraham, the spot start represented a not-so-subtle reward for how Fitts had carried himself in camp — while lining up with his pitching schedule.
“I think it was a good chance for the organization to let someone who has led by example — despite being new — show what can be done and how players can continue to improve even at the upper levels if they push themselves and they’re willing to be open minded about doing new things,” Abraham said.
“As a new guy in the organization, he has really exemplified what we’re trying to do with our pitchers pushing themselves on the mound, in the weight room, and with someone like him who has been in (velocity) training, he has really been willing to let his guard down and do some things that maybe he hadn’t done in the past and challenge himself and get some more out of himself physically than maybe he even knew he had.”"
https://www.masslive.com/redsox/2024/04/red-sox-rewarded-prospect-with-start-in-mlb-stadium-and-came-away-impressed.html