After a successful baserunning exercise yesterday morning, David Ortiz now believes he can live with the soreness in his Achilles tendon. And that means he believes he will be ready in plenty of time for Opening Day. “The main goal right now is to make sure I get to play down here — if I play down here, that means I’m good to go, you know what I’m saying?” said the designated hitter shortly after he ran at top speed along the bases on a back field. First he ran one base a time, then two, then all four, repeating some segments, checking in along the way with training staff and manager John Farrell. Ortiz said he ran better yesterday than he normally does, joking that he was not up for one of his rare triples. “I did it all today and nothing gave me a hard time,” said Ortiz. Farrell said that the running exercise added up to a “very encouraging day’’ for Ortiz. “Very aggressive — with each trip around the bases, he ran with a little bit more intensity,” said Farrell. “He came out of it feeling good about himself and I’m sure (today) will be another baserunning drill that will be less intense and probably not as much volume.” Ortiz will run today as long as the stiffness he expected to develop at some point either last night or by this morning is not overwhelming. He is getting used to the idea that by ramping up his exercise routine, he will loosen up calcification near the slight tear of the Achilles. The soreness is not expected to dissipate overnight, but eventually the doctors believe that it will cease to be an issue. In the meantime, Ortiz is learning how to cope with the lingering discomfort. “The soreness situation, we’re trying to manage right now, I’m trying to learn that part of it so if it happens during the season, I know how to manage it,” said Ortiz. “If I need a day off, I’ll talk to the manager about it. If I’m good to go, I’m good to go.