One of the most unpredictable Celtics seasons  in recent memory begins Wednesday, and in order to determine the likelihood of each player reaching his full potential, we’ll be examining them individually in this year’s Green Street preview with one form of this question in mind: “When’s the last time ‘¦ ?” Next up: Jeff Green .
When’s the last time a 27-year-old NBA veteran made the All-Star leap?
In the final months of last season, as Paul Pierce  and Kevin Garnett  stared father time in the face and Rajon Rondo  sat injured on the bench, Jeff Green rewarded the Celtics  with the potential they saw in him.
“Is he an elite talent in this league? I believe so,” Jason Terry  told WEEI in March . “If he didn’t have that surgery, you’d be talking about an All-Star. He’s an All-Star caliber player, and … I believe he’s the X-factor.”
Now, only Green stands in the way of an All-Star season. No Pierce, no Garnett and no Rondo for a while. The Celtics will give Green every opportunity to emerge as the star of this team — whether or not he ever does.
If his 32.5 field goal percentage (23.5 3P%) during the preseason is any indication, then this could be a long season for Green. But preseason generally isn’t an indication of anything. Green’s 17.3 points (49.3 FG%, 43.9 3P%), 5.0 rebounds, 2.7 assists and 1.1 blocks per game in the second half of last season is more like it.
It certainly isn’t unprecedented for a player to make his first All-Star Game appearance at age 27. Just last season, a 27-year-old Joakim Noah  became the 108th player to do so after his 27th birthday, and Tyson Chandler  earned his first invite at age 30. In the past few years, Andre Iguodola, Chris Kaman , Jameer Nelson, Zach Randolph , Gerald Wallace  and David West all made their first All-Star roster at either age 27 or 28.
Still, the odds of emerging as an NBA All-Star rapidly decline after age 26, when 52 players have made their first appearance. Here are the number of players who made their first showings at ages 27-34 (h/t AllStarNBA.es ).
Age 27: 38
Age 28: 34
Age 29: 13
Age 30: 12
Age 31: 5
Age 32: 2
Age 33: 1
Age 34: 3
In other words, if Green ever hopes to become an NBA All-Star, now’s the time.
Click on the links below to check out the “When’s the last time ‘¦ ?” questions for other Celtics.
Kelly Olynyk: When’s the last time a middle-of-the-pack draft pick won NBA Rookie of the Year honors? 
Gerald Wallace: When’s the last time a declining over-30 former All-Star enjoyed a career resurgence? 
Avery Bradley : When’s the last time a player emerged as a defensive standout, then made offensive leap? 
Vitor Faverani: When’s the last time an undrafted foreign-born rookie took the NBA world by storm? 
Brandon Bass : When’s the last time a frontcourt mate emerged in the wake of a blockbuster trade? 
Phil Pressey: When’s the last time an undrafted rookie point guard set the NBA world on fire? 
Kris Humphries: When’s the last time an offseason expiring contract acquisition was dealt midseason?