Castillo's absence, alongside that of several other teammates, including fellow linesmen Bobby Meeks, prompted Bowden to cancel the scrimmage planned for after Wednesday's practice as a precaution against additional injury.
"We really did it because we scrimmaged three days in a row and we felt like a fourth day was too much," Bowden said.
"We could have gone ahead and done it, but I think we would have been risking injuries."
There are also several other players, including linebacker Ernie Sims, who are being held out of contact for both their safety and the safety of teammates.
Sims said he expects to continue to wear a blue jersey until the start of the regular season.
The team has its next scrimmage planned for Friday evening. Bowden anticipates all players seeing at least some work, although in many the cases the work load will be light.
"If we had a scrimmage and everybody didn't get in there, we might have some plays afterwards where they did some work," Bowden said.