Italian champion Montepaschi Siena will be without forward Spencer Nelson for six weeks due to a shoulder injury. Nelson suffered an injury to his right shoulder during Sunday’s Italian League game against Grissin Bon Reggio Emilia. The club’s medical staff treated the player this week and decided that he will need six weeks of rest to heal before returning to action. Nelson, 33, joined Siena this summer from Gran Canaria. He scored 6 points and grabbed 8 rebounds in the Turkish Airlines season opener last week. Nelson, as a Euroleague rookie in 2005, joined the competition’s exclusive list of players with at least 20 points and 20 rebounds in a single game.