Mets shortstop Ruben Tejada is still considering filing a grievance against the Mets for the timing of his promotion to the major leagues in September, according to a person with knowledge of Tejada’s thinking. The person requested anonymity because the discussions were to remain private. The Mets waited to recall Tejada from Triple-A Las Vegas until Sept. 11, ensuring he fell one day short of three years of service time and, consequently, pushing his free agency back one season. The person described Tejada’s decision-making process as “ongoing.” A complete season of service time is 172 days. Unless a club surrenders control, a player must fulfill six seasons with a team to become a free agent. Tejada has accumulated two seasons and 171 days, one day short of three complete years. As a result, if he accrues at least 172 days each of the next three seasons, he will fall one day shy of six complete years, delaying his free agency until after the 2017 season. Mets general manager Sandy Alderson defended the club’s decision last month. “From our standpoint, we feel we have the right to bring up a player or not bring up a player,” Alderson said. “We have a right to determine when he comes up and so we exercise that discretion across the board with respect to eight or nine players or however many we brought up.” Tejada was recalled on Sept. 11, four days following Triple-A Las Vegas’s elimination from the Pacific Coast League playoffs. Reliever Sean Henn was summoned on the day of the loss. Two days later, outfielder Mike Baxter, catcher Juan Centeno, starter Aaron Harang and reliever Greg Burke were brought to New York. Tejada, who turned 24 in October, was the lone player recalled on Sept. 11. If he had been promoted Sept. 10, he would have three complete seasons on his résumé. “As you recall, we had staggered call-ups,” Alderson said. “I think we had some as early as the first of September and Ruben was the latest. It was partly a function of need. It was partly a function of Las Vegas and the fact that they were in the playoffs. And so it was a variety of factors that we looked at.”