The teen, identified by the medical examiner's office as 17-year-old Montreal Blakely, was shot in the first block of Osceola Lane at about 10 p.m. Saturday, police said.
Blakely was taken by a friend to a hospital where he was pronounced dead, according to police.
The Concord High School student played on the football team as a starting defensive back, according to coaches.
"He was a great kid, great teammate," head coach Brian Hamilton said. "He was super friendly and conscientious ... it's a real tragedy."
Many students at the school organized via social media to wear black today to mourn Blakely, and a vigil for him is planned at the football field at 7 p.m. Friday, Hamilton said.
The team's defensive coordinator, Randy Coddington, said Blakely was a team leader.
"He was very hard-working, got really good grades. Everyone on the team liked him," Coddington said.
San Francisco police said today they had no information on possible suspects.
Anyone with information about the case is encouraged to call the Police Department's homicide detail at (415) 553-1145, the anonymous tip line at (415) 575-4444 or send a tip by text message to TIP411 with "SFPD" in the message.