Update 3:59 pm: Mookie Betts has officially been placed on the seven-day DL for a concussion, with Jackie Bradley Jr. recalled to replace him on the roster.
Mookie Betts made a great catch on Tuesday against the White Sox, but the play didn't end the second he caught the ball: instead, he then flipped over the wall in right field, crashed into the ground, dropped the ball, and likely also suffered a concussion. According to the Boston Herald, Betts is probably heading to the seven-day concussion disabled list, which means the Red Sox will call up Jackie Bradley Jr. to take his place in center field.
Red Sox manager John Farrell was quoted as saying that Betts' symptoms are "consistent" with a concussion, so even if he ends up passing the tests MLB has in place to determine whether or not a concussion was actually suffered, the Red Sox should probably give him the time he needs to rest and recuperate.
There is no bright side to a concussion, so it's hard to be happy about Bradley making his way back to the majors. Given Shane Victorino has already been dealt and Alejandro De Aza is likely next on Boston's clearance rack, Bradley was in line to get some playing time over the season's last two months, anyway -- assuming the Red Sox don't include him in whatever deadline deal they end up making, anyway.
Bradley will now begin what is likely his last best chance to stick in Boston. While he's never hit in the majors for an extended period of time, he's in the midst of his best performance at Triple-A to date, batting .305/.382/.472 on the season with just 44 strikeouts in 318 plate appearances.
The center fielder, whose glove is one of the best in the game, doesn't need to be a lineup standout to have value. If he can hit around the league average, even a little below, his defense will do the rest. If he's to hit even that well, though, Bradley is going to need to learn to balance patience and aggression in a way that keeps pitchers from being in total control of every plate appearance. It's a huge step, and a necessary one, and failure to adjust to that could end up derailing a promising career.