By JORDAN GARRETSON
(AP) -- The Washington Wizards still aren't sure who they'll be facing in their first playoff series since 2008. The potential matchup could make a big difference between a likely first-round exit and advancing.
Washington can match its second-best record over the last 35 years with a road victory over the Boston Celtics on Wednesday night.
The Wizards (43-38) are one game ahead of Charlotte for the sixth seed in the Eastern Conference and one game behind Brooklyn for the fifth spot. A Nets victory in Cleveland on Wednesday would prevent Washington from passing them.
A win Wednesday for the Wizards would guarantee a finish no worse than sixth. Along with a Toronto victory at New York, they'd face the Raptors in the first round, while a Raptors loss combined with a Chicago win in Charlotte would lead to a first-round matchup with the Bulls.
But if Washington loses and Charlotte defeats Chicago, the Wizards will slide to seventh place and play Miami.
They won the season series with the Bulls 2-1, but dropped three of four against the Raptors. Washington split four games with Miami, including a 114-93 home victory Monday, though LeBron James and Chris Bosh were given the night off.
"We want to have an edge on Wednesday," coach Randy Wittman said. "... We secured a winning record on the road for this team and I want them to continue - even though there's one game left - to build and use that game as something positive going into the playoffs."
Trevor Ariza scored 25 as the Wizards shot 59.0 percent from the floor and was 14 of 29 from 3-point range. They've been one of the top 3-point shooting teams this season at 38.0 percent.
John Wall finished with just four points Monday but had 13 assists, his third game with at least 11 assists in the past four.
Looking to tie its second-highest victory total since its 54-win effort of 1978-79, Washington can take the season series from Boston for the first time in six years.
The Celtics (25-56), missing the postseason for the first time since 2006-07, fell just short of completing a big comeback at Philadelphia on Monday. Boston trailed by 19 at one point but Chris Johnson hit what appeared to be a tying 3-pointer with 0.9 seconds left. Officials, though, ruled he stepped out of bounds before releasing the shot and the 76ers hit two ensuing free throws to wrap up the 113-108 victory.
Kelly Olynyk, Jeff Green and Avery Bradley combined for 78 points with Olynyk scoring a team-high 28. Rajon Rondo had 14 assists and 11 rebounds after missing two games with a strained left shin.
"We definitely got a lot to play for, and it showed tonight," said forward Brandon Bass, who scored nine and shot 3 for 11. "We could've laid down when we were down."
Boston's Jerryd Bayless, Jared Sullinger and Kris Humphries are listed as questionable for Wednesday with knee injuries. Bayless and Sullinger have missed two games in a row while Humphries has sat out four of five.
Ariza has averaged 18.3 points in his last four against the Celtics while going 14 of 26 from beyond the arc.
Updated April 15, 2014