Red Sox pitching coach Dave Bush said Houck still needs to develop his splitter, which he introduced as a third pitch last season, Chris Cotillo of MassLive.com reports. "If he's going to be a consistent big-league starter over time, he's going to need a quality third pitch. He knows that and that's probably been on the top of the list," said Bush.
Houck dazzled in a three-start stint late last season, but Bush's comments suggest the right-hander will open the season at Triple-A Worcester. He threw a handful of splitters during his starts in 2020, relying heavily on the fastball-slider mix, so it makes sense for Boston to have him work on the third pitch in the minors.