The person said Cabrera asked the players' association to convey his desire to the commissioner's office and that an agreement to make him ineligible was reached Friday. The person spoke on condition of anonymity because no announcement had been made.
CSNBayArea.com first reported the disqualification.
Major League Baseball could not unilaterally disqualify Cabrera. It could only change the batting title rules for this year with an agreement from the union.
Serving a 50-game suspension, the San Francisco Giants slugger entered Friday with a league-leading .346 average, seven points ahead of Pittsburgh's Andrew McCutchen. Cabrera, the All-Star game MVP, was suspended Aug. 15 for a positive test for testosterone and is missing the final 45 games of the regular season.
Commissioner Bud Selig had said Wednesday "we generally don't interfere" in the batting title issue.
Qualifications for the batting championship are contained in the scoring section of the Official Baseball Rules, and Article 18 of baseball's labor contract says that if management and the union don't reach an agreement on proposed scoring rule changes that "significantly affect terms and conditions of employment" then the changes can't be put into effect until after the next complete season — which in this case would delay a modification until 2014.
But MLB and the union can change the rule at any time if they agree.
Cabrera has 501 plate appearances, one fewer than the required amount if the Giants play 162 games. Under section 10.22(a) of the Official Baseball Rules, he would win the batting title if an extra hitless at-bat is added to his average and it remained higher than that of any other qualifying player.
That rule came into play for the first time in 1996, when San Diego's Tony Gwynn won his third straight NL batting title, and his seventh overall. Gwynn hit .353 in 498 plate appearances and won when four hitless at-bats were added and his average still topped that of Colorado's Ellis Burks, Gwynn's closest pursuer at .344.
Baseball rules state a player needs to average 3.1 plate appearances for each of his team's games to become a batting, slugging or on-base percentage champion. But the last sentence of 10.22(a) says: "Notwithstanding the foregoing requirement of minimum appearances at the plate, any player with fewer than the required number of plate appearances whose average would be the highest, if he were charged with the required number of plate appearances shall be awarded the batting, slugging or on-base percentage championship, as the case may be."
Under Friday's deal, MLB and the union agreed that the sentence will not apply this year, leaving Cabrera one plate appearance short.
As the agreement is worded, the only way Cabrera would qualify for the batting title is if the Giants had a rainout and played only 161 games, in which case 499 plate appearances would be sufficient. Such a situation is unlikely this late in the season.