Nate’s agent tells the Boston Heraldthat negotiations are progressing nicely with his client: “Aaron Goodwin, the agent for Nate Robinson, said yesterday the two sides could reach a deal by the end of the week. ‘Things are going well,’ Goodwin said. ‘We’re just trying to get something worked out. But both parties are talking.’ According to a league source, the Celtics offered [Tony] Allen an amount similar to the $3 million he will receive annually from Memphis but were unwilling to guarantee the third year as the Grizzlies did. Unlike they had with Allen, the C’s don’t hold the so-called ‘Larry Bird rights’ to Robinson, and as a result, can’t go over the salary cap to give their backup point guard more money. Robinson, however, has professed a desire to return.”