The Portuguese playmaker insists he is ready to play his part in the club's Premier League relegation battle.
Baggies boss Mowbray does still have reservations over the player's fitness after a seven month spell on the sidelines with knee and calf problems.
However, Teixeira impressed stepping off the bench against Newcastle on Saturday and believes he is now ready to be handed his first top-flight start.
"I'm OK. I feel completely fit enough to be in the team," he told the Express and Star.
"My knee is not a problem now. I had a problem after the knee injury with my calf, but that is okay now and I feel ready.
"All players are frustrated and disappointed when they don't start games, but when this happens you have to train really hard and when you get the chance you have to make sure you do your best."
Learning curveWest Brom have had plenty of time to reflect on the shambolic defending which marred their 3-2 defeat to the Magpies, and Teixeira knows it is vital that lessons are learned from that game and implemented quickly.
"Newcastle scored three goals, one of them in the first two minutes, so after that it was very difficult," he added.
"But we need to keep going and stick together, because the next game is even more important now. We did better in the second half, but we were not happy about it because we didn't get a result.
"We need to look back at what we did wrong and try to correct it."