Zoom lens for sports photography

[Punisher911]

A 1.4TC should work on that lens without any problems - just make sure to either get a Sigma teleconverter or check to see if a nikon one will fit (generally speaking own brand are more physically restrictive as to what they can and cannot fit to - so do ask around before committing to a purchase).

In good light you should be fine to use the TC on the lens - and then indoors or in lower light conditions you can take it off for that extra stop of light.

for obvious reasons, please don't get a Nikon one.. seeing how you shoot a Canon T3...