Snell, the Rays' No. 4 starter, has struggled throughout the spring and continued to do so on Saturday, allowing four runs on six hits and a walk while striking out three in 4 2/3 innings.
"I'm happy with the way I attacked the zone," Snell said. "I feel like I took a stride. I felt more into it. More believing what I have. More aggressive. So definitely taking that [as a] positive, but I still know I have a lot to work on."
Josh Rutledge, who is the favorite to be Boston's 25th man, played first base for the first time and put the Red Sox up, 1-0, with a first-inning single off Snell.