OAKLAND -- Manager Bruce Bochy's initial concern Tuesday became a reality one day later as the Giants announced Wednesday afternoon that Joe Panik has a concussion and was placed on the seven-day disabled list.
"It was confirmed, he's got a mild concussion," said Bochy. "Our hope is when seven days are up he'll be good to go."
Panik sustained the injury on June 18 when he was hit on the head by a pitch from Rays left-hander Matt Moore.

In a corresponding roster move, San Francisco purchased Ruben Tejada's contract from Triple-A Sacramento. Tejada made his Giants debut at third base and batted ninth against the A's on Wednesday night at Oakland Coliseum, with Ramiro Pena continuing to occupy Panik's position in the infield.
Tejada joins the Giants after batting just .205 (9-for-44) in 11 games with Sacramento. Bochy, however, said he likes the versatility and experience the seven-year Major League veteran can bring to the infield, adding that he could slot Tejada at third, shortstop or second.
Tejada has been primarily a shortstop during his career, but he said he feels comfortable playing third. The former Mets infielder also said he feels fully healthy, about eight months removed from breaking his right leg after Dodgers second baseman Chase Utley viciously slid into him during the 2015 National League Division Series -- a play that inspired new base running rules for players sliding into second.
"I feel really good now, no pain, nothing," Tejada said.
Tejada began the season with the St. Louis Cardinals and hit .176/.225/.235 in 23 games. Following his release on June 1, the Giants signed Tejada to a Minor League contract on June 16.
Bochy said Tejada would primarily be used as a third baseman against left-handed pitchers.
Despite being visibly shaken while delivering the news about Panik's status a day prior, Bochy remained encouraged by how the Giants continue to perform given the influx of position players on the disabled list. The list now includes Panik, Matt Duffy, Kelby Tomlinson, Ehire Adrianza and Hunter Pence.
"We're doing a pretty good job," Bochy said. "Conor [Gillaspie's] doing a nice job, Pena, they've stepped up and played well. We do miss them. I want these guys back."
Worth noting
 The Giants recalled right-hander Chris Heston and placed him on the 60-day disabled list Wednesday to make room for Tejada on the 40-man roster. Heston is out with an oblique strain.
• The plan is for Giants reliever Sergio Romo to make appearances at Triple-A Sacramento on Thursday and Friday.
• Tomlinson, who is on the 15-day DL with a left thumb sprain, will begin playing for Class A Advanced San Jose this weekend.