The forward is on loan at the DW Stadium from Chelsea and has spent most of his time with the club on the bench. However given his impressive display against Hull City in the F.A. Cup third round on Saturday, a starting position against Aston Villa could be on the cards.
Sinclair told the club's official website: "It's a great feeling to have won the game. We didn't start too well in the first-half and didn't get much intensity out of our game. But we came out for the second-half showed the passion we have and managed to score a few goals.
"There are always people fighting for places in the team in training. Everyone works as hard as they can, and that's football, you have a big squad with plenty of competitiveness and at the end of the day the gaffer can only pick eleven players to go out there.
"Because it was my first full game in a while I was eager, fresh and feeling sharp. Basically I was ready to play and ready to be put in the action.
"I wanted to get my goal, and I was trying any way I could to get on the ball. When the chance came I turned on it and put in the back of the net, which I was very happy with.
"It obviously gets frustrating when you're not playing. I came from Chelsea where I wasn't featuring too often, but you just have to keep working hard and wait for the chance to come. Today I got the chance to show what I can do and hopefully I've given the gaffer a little bit to think about with my performance."
With Jason Scotland struggling to find form, Martinez may be tempted to play Sinclair from the start against Villa with Hugo Rodallega ploughing the lone furrow up front.