RE-INJECTIONS
Capital of Colorado? CEE
Degree in math? NTH
Taper? VCR
Stop on the Metro? ARRET [I know, but clever trumps all]
Theme: RE inserted between two words of a phrase
All five are very good.David must be a sports fan:
Went headfirst {SLID}
Diamond turns {ATBATS} [never understood why they’re not simply called “bats” or “ups”

]
Starters {ATEAM}
Court maneuver {PIVOT}
HSIA, really? It’s as arcane as some of my entries, before computers.
RATING:

Three grins = Loved it; Two grins = Enjoyed it; One grin = A bit bland for my taste; One teardrop = Not much fun