MIAMI GARDENS — Miami Dolphins quarterback Tua Tagovailoa — or, better yet, $212 million quarterback Tua Tagovailoa — appeared relieved and grateful Sunday when he made his first comments since agreeing to his lucrative contract extension Friday and officially signing the deal Sunday morning. But he’s also eager to deliver for the Dolphins and assure the team it made a worthwhile investment in him. Tagovailoa, in the past two years since coach Mike McDaniel and wide receiver Tyreek Hill arrived in Miami, has led the NFL in quarterback rating and yards per pass attempt in 2022 and then led the league in total passing yards in 2023. That, combined with making it through his first full season healthy last year, made it so that he could lock in his long-term future with the Dolphins before playing on the fifth-year option of his rookie deal this fall. But now, it’s about accomplishing what he hasn’t yet. “We haven’t won the games that we’ve wanted to win,” said Tagovailoa, speaking Sunday afternoon after the fourth Dolphins training camp practice, surrounded by family and Dolphins coaches and executives.