Sam Ryder provided further proof that golf is the most unpredictable of sports during the first round of the Valero Texas Open. The event leader carded the second-best round of his professional career after not being able to touch a club the day before.After his bogey-free opening round of 9-under 63, Ryder revealed that he was in doubt until Thursday morning whether he would be able to play in the tournament."Yeah, I had to withdraw from the Pro-Am yesterday," Ryder said. "Tuesday, after playing nine holes, I was hitting some drivers, everything was feeling really good with my swing, speed was ramping up and I kind of just felt something kind of strained a little bit in my upper back, kind of neck area and didn't feel quite right.""Kind of got progressively worse. My physical therapist is here, got some treatment but didn't practice the rest of the day. Wasn't able to go on Wednesday, didn't touch a club, yeah, didn't putt, didn't do anything.""I got out early today. My tee time wasn't until 12:40, I got out here at 9:30, I wanted to make some swings and just kind of see where I was at. If I wasn't going to be able to play, I wanted to let them know that in advance."Ryder also said that he fortunately started to feel better and that the warm weather at TPC San Antonio helped. Nevertheless, the 35-year-old went from almost not playing to achieving one of the best rounds of his life.The Winter Park, Florida native got off to a strong start with back-to-back birdies on holes one and two. He then cruised down the front nine, adding only a third birdie on the 8th to make the turn at 3 under.But Ryder saved his best for last, birdieing six more holes on the back nine, including the par-3, 249-yard 13th, considered the toughest hole at TPC San Antonio.His 18-hole lead is only the second of his PGA Tour career. His only previous experience in this position was at the 2023 Farmers Insurance Open, where he tied for fourth.Ryder has never won in more than 200 starts on the PGA Tour. Winning the Valero Texas Open would qualify him for the Masters Tournament, an event in which he has yet to make his debut.More Golf: Ludvig Aberg Contrasts Akshay Bhatia's Texas Open Approach ahead of Masters