Watt was forced to play the whole of last season in a brace to support his elbow, which he injured in a training camp last year.
The 24-year-old appeared to have fully recovered from the injury when he took part in pre-season training without the brace last week, but he has since revealed that he will be forced to wear it for the upcoming campaign.
However, Kubiak insists that the injury has not been aggravated and that the brace is just a precautionary measure after Watt felt soreness in his elbow on Thursday.
"His elbow's just sore. We brought him out here to practice today, wanted to keep him out of contact. As you all could see, the majority of practice was contact," Kubiak told reporters.
Watt set a franchise-record of 20.5 sacks during last season and was named the AFC Defensive Player of the Year.