Sometimes appearances can be deceiving. For instance, now that it’s the middle of the NBA season, it seems clear that a few teams have established themselves as legitimate contenders – the Spurs and Suns in the West, the Heat in the East – while others seem to be miles behind. But don’t be lulled into thinking this is how things will be in June.

Sitting behind those big three are what I call the lurkers – the teams that, with one key trade or a revival from a key player, have a chance to make a run in the second half of the season and stampede through the playoffs. If this seems far-fetched, allow me to jog your memory.

A year ago, the Detroit Pistons were a decidedly unchampion-like 34-24 after 58 games. Then Joe Dumars made a deal for Rasheed Wallace and Mike James at the trade deadline, and the rest is history. Detroit went on a 20-4 tear over the final two months, cruised through the Eastern Conference playoffs, and ripped apart a favored Lakers team in the Finals.

With the right player either arriving or emerging, several teams have the potential to do the same thing this year. Here’s a look at some of these lurkers and what they need to make a second-half charge, as they’re likely to be the most active teams at the February 24 trade deadline.

SACRAMENTO (25-11) Sacramento is the perfect example of a team lurking just beneath the surface, quietly accumulating wins while everyone forgets about them. The Kings aren’t good enough to win a title as presently constructed, but they aren’t far off at 25-11 despite the loss of Bobby Jackson for the season.

Last week’s trade of Doug Christie for Cuttino Mobley provides an offensive spark, but this team still needs help in the backcourt behind Mobley and Mike Bibby – right now journeyman Eddie House is what passes for depth. They have few assets with which to obtain another point guard, but don’t count out General Manager Geoff Petrie, who ranks among the best talent evaluators in the business.

DALLAS (23-12) Reinvented as a defensive team this year, the Mavs have enough tools to make a run even without a trade. The problem is that several important pieces have misfired thus far. Off-season pickup Erick Dampier has played well below his standard of the previous two seasons, depriving Dallas of what they thought was an answer in the middle.

On the outside, Marquis Daniels has been hobbled by an ankle injury after an electrifying finish to his rookie season pegged him as a rising star. Rumors of a trade for Jason Kidd dominate the discussion in Dallas, but a healthy return from Daniels and a wake-up call for Dampier could have an even greater impact. With Dirk Nowitzki enjoying a career year, this is a team to keep an eye on throughout the spring.

SEATTLE (27-9) Despite a great start to their season that has them on pace for 60 wins, it’s hard to find anyone who thinks this team can win the championship. The missing piece in Seattle is another reliable frontcourt performer.

Danny Fortson has been great but can only play about 20 minutes before fouling out on most nights, forcing the Sonics to go with the under-motivated Jerome James or the inexperienced Nick Collison in crunch time. Here’s the interesting part: They have the piece to trade if they’re really interested, because high-scoring guard Ronald Murray doesn’t have a role in Seattle’s crowded backcourt.

DETROIT (23-14) Hey, does this look familiar? Despite last year’s struggles the Pistons are only a game off last season’s pace, and are riding a six-game win streak that included an impressive flogging of Phoenix yesterday afternoon. But they still could use a boost.

This year, it’s the bench that needs addressing. The Pistons’ second unit was a strength a year ago but the off-season defections of James, Mehmet Okur, and Corliss Williamson have left it in tatters. The challenge for Dumars this February is to find a reserve who can provide some points. A trade could be one answer – it worked last year – but another could be little-used youngster Darko Milicic.

MINNESOTA (19-17) Right now, the T-wolves are hamstrung by lackluster defense, but they could turn things around fairly quickly if they are willing to take on salary. Latrell Sprewell’s expiring contract is quite a carrot for a team that wants to unload an expensive guard with a few years left on his deal – Boston’s Ricky Davis, for example, could be packaged with forward Raef LaFrentz. The problem is that this would seriously increase the T-wolves’ luxury tax liability, so it’s probably a no-go from owner Glen Taylor.

CLEVELAND (22-14) Sound ludicrous? Maybe it is. But it’s hard to watch this team and not wonder how much better it would be if it had a shooter to stretch out defenses. Cleveland’s shooting guards – I use the term loosely – have unleashed a profusion of bricks on unsuspecting rims, forcing LeBron James to drive into a slew of defenders camped in the lane.

The Cavs have few tradable assets, however, so they might decide to wait until next year. They can afford to be patient given King James’s youth, and with a wad of salary cap space opening up this summer, they’ll have their pick of a bumper crop of shooting guards.

INDIANA (18-17) The Pacers’ issues are a bit more complicated than those of the other teams because the suspension of Ron Artest deprived them of their second-best player. Fortunately, nobody has more assets to trade at the deadline than the Pacers, who are easily the NBA’s deepest team. Additionally, they have two X-factors trying to return to health: interior wrecking ball Scot Pollard and talented 7-foot swingman Jonathan Bender. Should either emerge, the Pacers will be dangerous come April.