derek harper was the 11th pick by the mavs in the 1983 draft. in his 11th season with the mavs, he was traded to the knicks mid-season, and there he wore #11 in his three in NYC, ending in 1996 when he had 11 playoff three-pointers and 11 playoff free-throws. the next year he was back with the dallas mavericks, who were truly horrible that year and had no chance of making the playoffs. the mavericks tried to trade him to the jazz, but harper nixed the trade and then justified his decision when he famously remarked, "you go live in utah." had he come to the jazz, he would have been on the team for two finals runs, but instead he failed to make the playoffs again until his 1999 stint with the lakers (where he had a playoff PER of 11.3) and as such fell short of 11 playoff appearances (instead getting stuck on 10 years in the playoffs).
11 is also the number of career playoff games rony seikaly had under his belt as of the february 1998 trade deadline, when the jazz made a move for the greek/lebanese center. had seikaly joined the jazz that spring, he would have more than doubled his career playoff games in that one year alone (and possibly helped the jazz get over the top in their title quest, which fell short again that june), but instead he allegedly shot down the trade. he had talked to karl malone (whose all-star jersey number was #11, btw) about how excited he was to come, but quietly backed out and used a foot injury as the reason he didn't report. after that trade fell through, the magic traded him to NJ for ex-jazz david benoit and a future draft pick that orlando used to select matt harpring (along well as kevin edwards and yinka dare). seikaly then appeared in 3 playoff games for NJ that season when they were swept in the first round. he never again returned to the playoffs.
raja bell wore #11 for the sixers and mavs before he came to utah the first time. gordan giricek wore #11 for the sixers after the jazz traded him there for kyle korver. ronnie brewer wears #11 for the bulls. marty byrnes wore #11 for the pacers after he left the jazz. john crotty wore #11 for the cavs and heat after he left the jazz. gail goodrich wore #11 in his first three seasons with the lakers, about a decade before he came to the jazz. rickey green wore #11 for the bucks after he left the jazz. linas kleiza -- whose draft rights the jazz traded to get up to deron williams in the 2005 draft -- wears #11 for the raptors. karl malone wore #11 for his one season with the *gag* lakers. former jazz coach butch van breda koff wore #11 in his one season with the knicks during his playing days.