For the third time this season, the Houston Rockets will face off against the Portland Trail Blazers, this time in Houston. Somehow, both times these two teams met ended in overtime contests. The Rockets have yet to win in overtime against any team, and find themselves needing to get a win to pull the season series to 2-1 in Portland’s favor, and a chance to tie the series by season’s end. The Blazers sit just a single game behind the Rockets, waiting in the 9th seed to grab Houston’s playoff spot, making this contest a must-win for Houston.The Houston Rockets and the Portland Trail Blazers have both exceeded expectations all season long, and now two supposed lottery teams face off with a playoff spot (at least temporarily) in the balance. In the previous two meetings, the teams looked about as evenly-matched as possible, with both contests decided in overtime. This time, however, the Rockets enter the arena not as a group of young players getting to know each other, but as a team expected to make the playoffs. As expectations rise, the Rockets face pressure to win a game which looked, scant weeks ago, like just another Friday.Rookie of the Year candidate (and front-runner, realistically) Damian Lillard torched the Rockets in their last matchup, November 16th. He (and another Blazer) willed Portland to that win, closing out the evening with 27 points in a breakout game. He’s one of the most lethal scoring point guards in the league, much less in his rookie class. Lin, Douglas, and any Rocket who gets switched onto him will have to play exceedingly smart defense to avoid a repeat. Unfortunately, defense isn’t Houston’s strong suit.Of course, doubling Lillard only goes so far when the Blazers have one and a half unguardable players beside him. LaMarcus Aldridge remains the Blazers’ rock, and he’s as steady as one. Few big men in the league have as reliable a combination of post moves, mid-range shot ability and turnaround skill that Aldridge does. Patterson and Asik both sport solid defensive chops in the post, and Houston may be one of the few teams liable to guard Aldridge with any efficacy. This won’t matter, however, if that half-unguardable player shows up.On November 16th, 2012, Nicolas Batum had his way with the Rockets, racking up 35 points on 19 shots, and hitting 5 huge three-pointers. Batum has shown flashes of greatness all season, but hasn’t been able to do it consistently. His defense is always solid, and his three shot is reliable, but on some nights he shows an ability to drive the lane that can destroy other teams.Houston’s bench, while probably still without Carlos Delfino (right elbow), has shows great improvement and cohesion since November, and should be able to fare much better against Portland’s notoriously thin bench. Another good sign for Houston is the difference in average margin between these two clubs: Houston sports a +2.9 on the season, while Portland sits at -1.82 points per game. With half the season over, stats like that take more meaning, and portray Portland as a team overachieving quite a bit.This is a game we’ve watched twice already, but Houston has to be careful not to let it turn into a re-run. The Rockets have earned a spot in the top eight teams for now, but have to continue to prove that they can beat the teams below them in the standings. The Trail Blazers have climbed up to the ninth seed, and are dangerously close to pulling even. Any game between two teams at the bottom of the playoff bubble will be hard-fought, and this game should be no different. Neither team can afford to lose.