Had Domonic Brown known he would miss at least two games when informing a team athletic trainer of concussion-like symptoms he may have hidden his dizziness Tuesday night. His head had slammed into the warning-track dirt in left field when he unsuccessfully dove for a fly ball.

"I feel good" Brown said a day later. "I feel like I'm back to normal honestly."

But the Phillies outfielder cannot play until Friday at the earliest. Major League Baseball's protocol calls for extensive concussion testing before a player can be approved for action. The process was initiated Tuesday night testing was conducted Wednesday and more will be administered Thursday.

Even if Brown misses just two days it is a huge blow at a critical time. Brown leads the team in home runs and runs scored. He assumed Ryan Howard's cleanup spot in the lineup when the slugger succumbed to knee surgery. Delmon Young ascended to that spot Wednesday.

Brown expressed optimism that a Friday return was reasonable. If his symptoms worsen or he does not pass those tests he could be placed on the seven-day disabled list.

Brown's injury prompted the promotion of light-hitting utilityman Michael Martinez from triple-A Lehigh Valley. The Phillies played the previous four games with three catchers and four outfielders. Catcher Humberto Quintero was designated for assignment to make room.

Martinez is a career .186 hitter. He has twice been outrighted off the 40-man roster in the last calendar year. His .506 on-base-plus-slugging percentage is the fifth-worst all-time for a Phillies position player with at least 350 plate appearances.