"My salary would have tripled what it is now," said Twellman, who has completed one year of a four-year contract worth $395,000 annually. "There has to be an adjustment and the fair thing to do would be either to sell me or adjust my pay accordingly."Preston is doing pretty poorly in the Coca Cola Championship (the league right below the Premiership) and they might actually get relegated to the First Division. That might have played a role in MLS' refusal to send Twellman over there - they don't want the US' best goalscorer stuck on a 3rd tier English side.
The same situation happened to Shalrie Joseph last year when Celtic put in a $2 million offer. During the offseason after Celtic's offer, Joseph got a raise. Since MLS just raised the salary cap level, I'd hope that Twellman gets the same. However Twellman already makes the league maximum for non-marketing cash cows, so Kraft would have to pay Twellman out of his own pocket by making Twellman the designated player. Given Bob Kraft's notorious cheapness when it comes to the Revs, I think that's unlikely.
End result, an unhappy Twellman to go along with the unhappy Joseph.