The 32-year old Wolves, Celtic, Rangers and Cardiff City man was used as a second-half substitute in the Whitecaps scoreless draw with Real Salt Lake in the final regular season match on the weekend so was given a full run in the reserves to get his match fitness up to scratch.
Miller admits it is weird to not be consistently suiting up with the seniors but says he is simply doing what head coach Martin Rennie thinks is best.
"It's a very different role - obviously one I'm not too happy with and not too used to," Miller said.
"Obviously I want to play. That's what my mind is going to be focused on until told otherwise. I'll go out and work hard."
He added: "You never know, you could be needed after five minutes in any game. The last time I never (started) was against Colorado (back on September 24) and I came on at halftime so you need to be prepared."
The Whitecaps take on Western Conference's fourth-placed LA Galaxy in a playoff knockout on Thursday after finishing fifth on the same table.