In 2000, Twellman signed with German
Bundesliga club
1860 Munich. He spent two years with the team, but played for the reserve team in Division III, and never played above the reserve level. Twellman returned to the U.S. when he was drafted second overall by the
New England Revolution in the
2002 MLS SuperDraft on February 10, 2002. He made his MLS debut in the Revolution's season opener on March 23, coming on as a 67th minute substitute for
Álex Pineda Chacón in a 3-1 loss to the
MetroStars. He scored his first MLS goal, and made his first MLS start, on April 20, 2002, scoring in the 10th minute of a 2-0 victory over the Columbus Crew. In Twellman's first season in MLS, he established himself as one of the best players in the league, scoring 23 goals. On May 11, 2002, Twellman scored the first (and second) ever goals at
Gillette Stadium in MLS league play, in the Revolution's 2-0 win over the
Dallas Burn. He finished second in league MVP voting, and was named to the 2002
MLS Best XI. In the 2003 season, despite being beset by a number of injuries, Twellman finished tied with Carlos Ruiz of the L.A. Galaxy for top goalscorer of the league with 15. His production went down in 2004, as he ended up with just nine goals. Twellman's best MLS season came in 2005, winning both the
Major League Soccer MVP Award and
MLS Golden Boot, and finishing the regular season with 17 goals. He was also named to the 2005
MLS Best XI. Twellman was the target of transfer talk when
Odd Grenland of Norway reportedly made a $1.2 million bid for him, which MLS rejected. In February 2007, New England announced they had signed Twellman to a four-year contract, reportedly worth $5 million. In 2007, Twellman won his first title with the Revolution: the
US Open Cup, a season in which he finished third in MLS in goals scored. The Revolution also won the Eastern Conference title, with Twellman scoring a spectacular bicycle kick against the Chicago Fire to secure the Revs' spot in the
2007 MLS Cup. Twellman scored the opening goal of the 2007 MLS Cup against Houston Dynamo. However, this would be New England's only goal as they would go on to lose their third straight MLS Cup by a score of 2–1. In January 2008, English
Championship team
Preston North End attempted to entice Major League Soccer and the New England Revolution to sell Twellman. Preston initially advanced an offer of $1.7 million, but MLS and the team rejected that offer, rejected another offer of $2.5 million, and then rejected another bid for $3 to $3.5 million, which would have been the fourth highest and possibly the second highest transfer fee in MLS history to date. Twellman played the rest of the 2008 season, but due to lingering symptoms from his whiplash and concussion, he played only two games in 2009. Twellman had planned to make his return during the 2010 season, but he was unable to play that season and was placed on the season-ending injury list. After struggling to find any playing time over the past three seasons in MLS due to his head injury, Twellman announced his retirement from the game at the end of the 2010 MLS season. ==International career==