Fisher joined up with the Oklahoma City Thunder after getting traded away by the Lakers during the season, choosing to buy out of his own contract with the Houston Rockets and sign with a team he thought had a chance of winning the NBA title.
Fisher has already won five championship rings with the Lakers, but now his new team is a victory away from knocking Los Angeles out of the playoffs. The Thunder get their first chance in Game 5 Monday night in Oklahoma City.
Fisher has had to put his personal friendship with Kobe Bryant on hold during the series. The two greeted each other the first time Fisher came off the bench and checked in during Game 1 but otherwise are adversaries as long as the Western Conference semifinals go on.
"As much history as we have, there's no holding back in terms of trying to advance to win the championship," Fisher said. "Personal friends or brothers or however close you are to somebody, it's about winning. He knows that better than anybody.
"I learned that and accomplished that right alongside with him, and so we feel the same way."
Fisher played with Los Angeles for 12 1/2 of his 16 NBA seasons, and the only other time he made the playoffs with another team was in 2007 with Utah. But the Jazz didn't face the Lakers.
Los Angeles sent Fisher away at the trade deadline in March, when they added a first-round draft pick, point guard Ramon Sessions and backup forward Jordan Hill to try and improve for the stretch run. The 37-year-old Fisher chose his age as his jersey number with the Thunder, trying to make a statement that he could still play.
Statistically, Fisher has struggled in the series. He has averaged just over four points and one assist per game and his playing time has been cut back. Fisher's plus-minus is the worst of any Oklahoma City player, with the Lakers outscoring the Thunder by 12 points while he's on the court.
Yet coach Scott Brooks believes there's another way to measure the impact of Fisher, who has never put up big numbers — averaging 8.6 points and 3.1 assists — over his career.
"He loves the game, he has passion for the game and he's a winner," Brooks said Sunday after Oklahoma City flew back home, landing after 5 a.m. because of thunderstorms. "I can never emphasize that enough: He's a winner, and you can never have enough of those on your team. He has won before. He has won at a high level and many championships."
Before the series started, Fisher informed Oklahoma City of the Lakers' tendencies. During games, he has regularly pulled aside teammates for a few words of guidance. One of L.A.'s locker room leaders is now working for the enemy.
"Leadership, you can't put a win total on it but you know the effect that it's having on our guys," Brooks said. "He talks, he communicates, he's a great leader. He's going to be a great leader in whatever profession he chooses after basketball."
Perhaps his biggest contribution yet that has counted in the box score was a 3-pointer that sparked the Thunder's comeback from a 13-point, fourth-quarter deficit in Game 4. Oklahoma City was down 91-78 with 8 minutes left before Fisher hit only his second basket of the game.
"It was huge. It cut it to 10. That's just kind of like that magical number. It always seems to be in reach if you can get it to 10 or under," Brooks said. "That shot was big."
Lakers coach Mike Brown said he thought at the time of the trade that his team might miss Fisher's leadership, experience, toughness and intelligence. But he never envisioned Sessions, who is 11 years younger, simply replacing Fisher.
"The roles are different," Brown said. "Derek Fisher was our starter. Derek Fisher for these guys is a backup. I don't think you compare the two situations because we were relying on him for a completely different role than what Oklahoma City is relying on him for.
"I don't know if anybody would disagree the combination of starting (All-Star Russell) Westbrook and Derek Fisher as a backup is a pretty good combination because you're young plus you're experienced."
Bryant poked fun at Fisher, calling him a "midget" after he was able to hit shots over him when they ended up matched up against each other briefly in the fourth quarter. Bryant says Fisher never beat him at one-on-one in nearly 13 years together with the Lakers.
But team against team, Fisher may finally get some bragging rights on Bryant for they get back to being friends.
"At some point, we'll reconnect and be what we always will be," Fisher said, "and that's brothers."