It was with more than merely national pride that David Ortiz glanced up at a television in the Red Sox clubhouse yesterday and smiled at the sight of another victory for the Dominican Republic in the World Baseball Classic. “Oh, I’m loving it,” Ortiz said. “I’m loving it.” Ortiz hasn’t had much to smile about lately, the soreness and inflammation in his heels almost certain to sideline him for the start of the season. A week after being shut down from physical activity, the designated hitter ran on an underwater treadmill yesterday and said he feels “a little bit” better — but still not good enough to ramp up his workouts or commit to manager John Farrell’s suggestion that Ortiz may take batting practice tomorrow. “I’m not there yet,” Ortiz said.