<p>All-Star point guard Fox has yet to play in the conference finals after injuring his right ankle in the second-round series win over the Minnesota Timberwolves.</p><p>Rookie Harper, who has stood in for Fox in the starting lineup, left Wednesday's game-two defeat with a thigh muscle injury.</p><p>The Spurs opened the best-of-seven series with a spectacular double-overtime victory in game one, with the Thunder bouncing back on their home floor in game two.</p><p>The Spurs will host games three and four on Friday and Sunday.</p><p>The winner of the best-of-seven series will advance to the NBA Finals.</p><p>The Thunder are also hurting. Swingman Jalen Williams, who has been hampered by a hamstring issue since the start of the playoffs exited after just seven minutes in game two and is questionable for Friday's game.</p>