Wilson, 33, was injured when a ball hit by Yorvit Torrealba struck him in the left side of the head. He was bleeding but never lost consciousness and wanted to continue the session.
Instead, members of the Angels' medical had him carted off the field to get a CT scan as a precaution.
"He was very cognizant; he was aware of what was going on, what was happening, and never lost consciousness," Angels GM Jerry Dipoto said, according to MLB.com. "The initial read is that neurologically he is fine."
Wilson later tweeted:
Everything is fine, except that pitch I threw. Shoulda caught it. Thanks for the #PMA - lesson is to not pitch to contact! Haha
- C.J. Wilson (@str8edgeracer) February 25, 2014
Wilson, who went 17-7 with a 3.39 ERA last season, wasn't the only member of the Angels injured on Tuesday.
Outfielder Josh Hamilton suffered a strained left calf during a base running drill, according to reports.
After undergoing an MRI, the former AL MVP left the team facilities in crutches.
Hamilton, 32, batted .250 with 21 home runs and 79 RBIs last season -- the first of his five-year, $125-million deal with the Angels.