Arencibia suffered the injury during the second inning when A's third baseman Brandon Inge fouled a ball off his bare hand. X-rays revealed a non-displaced fracture that will not require surgery but still involves a lengthy rehab.
"I knew as soon as it hit me, I knew we had a problem," Arencibia said. "It kind of went numb and I couldn't really feel much in my hand. It started turning purple and I knew it was not going to be a good ending."
Arencibia had his hand and lower arm heavily wrapped after the game and will have a cast put on Thursday morning. The estimated six-week time frame would keep the second-year catcher out until the first week of September.
That would be close to the end of the season, but after the game Arencibia did not sound like a person whose 2012 campaign was in jeopardy. The native of Miami insisted he would make a return later this year and remained optimistic his teammates will be able to fill the void during his absence.
"I drink a lot of milk, so I feel that at some point the bone's going to heal and I'll be back," Arencibia said. "I'm going to write down some notes and remember how I'm feeling now so that when I get back I don't miss a beat. Hopefully we're in contention and playing meaningful baseball."
Arencibia's injury is another serious blow to a team that has been hampered by injuries for the past two months. Toronto currently has 11 players on the disabled list and has had 13 on the year.
The injury woes began in June when starters Brandon Morrow, Drew Hutchison and Kyle Drabek were all placed on the DL. Since then, the injuries have also begun to affect the position players, as Jose Bautista was shut down last week with a sprained left wrist.
Despite the number of injuries, Blue Jays manager John Farrell said his club's situation isn't that much different from ones other teams have encountered.
"There are teams around the league that have had equal number of injuries and to important players," Farrell said. "To compare to anybody else, that's fruitless in my mind. We have to work with what's currently available to us and not make any excuses for it.
"I think we've done an excellent job to date. ... We still have quite a few games left to play, the schedule's not going to get any easier and we're certainly not going to use this as an excuse from the outcomes of the games going forward."
Veteran Jeff Mathis will now step into a starting role while utilityman Yan Gomes assumes the backup catcher position. Top prospect Travis d'Arnaud would have received consideration for a callup, but his season is likely already over because of a left knee injury.
Arencibia entered play on Wednesday riding an impressive hot streak. He was hitting .357 (15-for-42) with four doubles, five home runs and 12 RBIs in his past 13 games. He also had homered in three consecutive games.
The injury alone would have been tough for Arencibia to deal, but he says it becomes even more challenging considering the timing and everything else that has gone on with the club this year.
"I was trying to do my best to fill in for Jose because obviously he went down," said Arencibia, who is hitting .242 with 16 home runs this year. "This team is resilient and I know that they will find a way to come back and bounce back with or without me. Now, it's without me for some time. They'll be fine, there's 25 guys going to be here and they're all going to be pulling together and they're going to figure out a way to win."