Arsenals striker Alexis Sanchez is on the verge of worsening his thigh injury

striker Alexis Sanchez is willing to risk the prospect of worsening his thigh injury by playing in Chile’s 2018 World Cup qualifier against Uruguay on Tuesday, potentially infuriating manager Arsene Wenger.Sanchez suffered “a low-grade muscle tear” in his right quadricep while training with his national team earlier this week, with a scan revealing the damage and ruling him out of Thursday’s World Cup qualifier against Colombia.But with Chile struggling in the South American World Cup qualification, Sanchez is ready to risk further injury in order to return much earlier than expected. Chile are currently in fifth place in the South American table, with only the top four guaranteed a place at the next World Cup in Russia. Finishing fifth would mean they would face a play-off against a nation from the Oceania region, with the winner qualifying for Russia 2018.    Read moreWilshere prepared to leave Arsenal permanentlyArsenal are still in contact with the Chilean Football Association over Sanchez’s condition, but they will be dismayed to read of Sanchez apparently telling friends that he will play next week despite the threat of worsening his muscle tear.According to Chilean newspaper El Mercurio, Sanchez told friends: "It is hurting a bit but I'm fine. I'll be back for Tuesday."However, there are already fears that Sanchez’s injury could be worse than originally thought, despite Chile cutting down his expected recovery time from six weeks to three. A source close to the national team claimed that a muscle tear can “evolve” in the 24 hours after it happens, and it could get worse in the time between Sanchez having his initial scan and a secondary one in the next few days."The ultrasound was performed immediately. The doctors commented that with these injuries you must wait 24 hours to determine the recovery time, because the tear evolves," the source told El Mercurio.