When Derek Jeter talks today at Yankee Stadium about a second fracture in his left foot that has him shelved indefinitely, don’t expect the Yankees’ captain to deliver a time frame for his return. “We are trying to stay away from putting [a time frame] on it other than after the All-Star break at some point,’’ general manager Brian Cashman said Wednesday before the Yankees’ 3-0 loss to the Rays. After fracturing his foot last October and having surgery, Jeter was confident he would be ready for Opening Day. But late in spring training the foot didn’t allow him to run and he started the season on the disabled list. A week ago today it was announced that Jeter has a second, but smaller, fracture in the same foot. Jeter is back in a walking boot and nobody is venturing a guess when the Yankees will get him back. Eduardo Nunez has started 16 of the Yankees’ 20 games at shortstop and while his defense — the biggest concern going into the season — has been solid, Nunez is batting only .184 (9-for-49) and hitless in 11 at-bats with runners in scoring position. Nunez made two stunning plays in last night’s 3-0 loss to the Rays. In the second inning he went up the middle to rob Yunel Escobar of a hit and robbed Jose Molina of hit in the sixth by going deep in the hole. Nunez’ second-inning single was one of the Yankees’ four hits.