"Obviously, he's not with us," Mattingly said. "Guys have their reasons for whatever they do. I don't really judge that."
The manager acknowledged rumors and trades are simply part of the business and it's natural that some fall through like the one with Lee.
"It's this time of year," he said. "I don't try to get too excited about anything. We talk about all the different things [general manager Ned Colletti] is talking about and if they happen, they happen. If they don't, they don't."
In the meantime, that means James Loney is still the first baseman in a platoon with Juan Rivera.
Loney, who was in a 1-for-27 slump heading into the weekend when rumors first started, had an encouraging game Sunday night. The first baseman had an RBI double in the seventh and finished the 8-3 win over the Mets with a pair of RBIs.
"James has been an enigma," Mattingly said.
Loney went into Mattingly's office after Sunday's game and told the manager that he is back and confident.