Diaz (head) was activated from the 10-day injured list Tuesday, Chandler Rome of the Houston Chronicle reports.
Myles Straw was optioned down to clear room for Diaz, who ended up missing the minimum after being briefly hospitalized for dizziness and lightheadedness. Diaz will not immediately slot into the lineup, but with Carlos Correa (back) on the injured list, Diaz will probably be in line for three-to-four starts per week.