Floyd returned to Chicago to have an MRI on Sunday, and it revealed no structural damage, according to Ventura. He will be re-evaluated later in the week.
Floyd is 7-8 with a 4.54 ERA in 17 starts this season. He has allowed 101 hits, 52 earned runs and 31 walks and has struck out 91 batters in 103 innings. He's allowed four runs in his last four starts.
"(We'll) kind of see of how he is when we get him to Boston," Ventura said on Sunday. "As far as looking at the MRI, he said everything was structurally good. It's more soreness. It shouldn't be a DL, but you never know, once he gets back see how much soreness he has."
Ventura believes Floyd's last start may have led to the injury. Floyd threw 100 pitches in that July 7 victory over the Toronto Blue Jays and a season-high 122 pitches in his previous start on July 1.
"I think the last start he threw a lot," Ventura said. "It's just one of those maybe he was throwing a little different than he was before. Just to clear his mind, our mind, it's nothing structural. It's easy for me to say general tendinitis, but it's better than other things you can get."
"It's one thing after another," Ventura said. "It is, but then again that's part of having a long season. You're always going to have stuff like that. It's unfortunate, but you just keep moving, just keep playing, find somebody who is going to fill in, move guys around, be able to do it. So far, we've been able to do that."