his role is diminished since the injury, but don't forget initially James Jones was slated as the starter but went down to injury. Webster got that starting spot by default and it wasn't like he was doing a bang up-job with it. There are tons of SFs around the league who have been better then him... Portland finally got one too. With his beautiful stroke and long limbed frame, Martell always looked the part, but he hasn't added much to his game in his first 3 years and you can only earn PT on promise for so long. That his level of outside threat has been matched by several other players on the roster doesn't help his cause either. Maybe the starting role and MPG came too easy for him... maybe a little bench time will give him the focus he seems to lack? Or maybe what we've been seeing is what to expect more of? He's on a reasonable contract and seems to be a decent enough teammate... if he winds up the 10th man or plays his way back into the regular rotation, I have no problem with him on the roster as long as he stays positive and focused. STOMP
I have zero problem with Martell as the 10th or 9th (or even 8th) man on this roster, he's not a massive liability at either end of the court, he's just not exactly a massive asset either, even his contract isn't too awfully overinflated; it's for quite a bit below the MLE and while it might be a tad much to pay a guy if he improves no further (an outcome I give a fifty-fifty chance) it's not like he'd be impossible to move in a trade down the line and he's still got a reasonable amount of upside left (sort of).
Webster is paid reasonably for what he is--an average reserve. If he "breaks out" (which I'm not holding my breath on, but is certainly within the realm of the possible), Portland stands to clean up on the deal. The Blazers really can't lose on the deal in any significant way unless he misses big chunks of another season or two in the lifetime of the contract.