YES Network.com

Powerade may be a sports drink that replenishes athletes’ bodies, but they’ve also possibly poured some more salt into the fresh wounds of Boston Celtics fans.

As first spotted by Matt Burke of Boston’s Metro newspaper, Powerade has placed an electronic billboard along the south side of Interstate 93 in Medford, Massachusetts – just a few miles from the Celtics’ home building, Boston’s TD Garden – that congratulates Miami Heat forward LeBron James on winning his first NBA Championship last month.

The billboard, which also appears on the sports drink icon’s Facebook page, reads, “Congrats, LeBron. Championship has a nice ring to it.”

Boston fans may have already been a little bitter towards LeBron, as the Heat have dispatched the Celtics from the playoffs two straight years and it was the reigning league MVP himself whose stellar performance in Game 6 of this season’s Eastern Conference Finals (at TD Garden, no less) helped Miami overcome a 3-2 series deficit to top the Celtics en route to the title.

And, to make matters worse, earlier this week Miami signed 10-time All-Star Ray Allen, who spent the last five seasons in Boston and helped lead them to the NBA Title in 2007-08, for a salary reported to be half of what Boston may have been offering him to return.

Now, however, when folks in Beantown commute on I-93, the rush hour traffic might not be the only thing giving them a headache.