The San Antonio Spurs are finalizing a five-year, $45 million contract extension for center Tiago Splitter, league sources told Yahoo! Sports. Splitter, 28, developed into an important part of the Spurs' run to the NBA Finals and had significant interest around the league as a restricted free agent. Portland had strongly considered signing Splitter to an offer sheet near the $9 million salary that Spurs paid, but Splitter's representatives and San Antonio worked out most of the details of an agreement on Monday night and into Tuesday, sources said.