He spent the majority of his career with his boyhood club Malmö FF, as well as a notable five-year stint with German Bundesliga side Werder Bremen.

[3][4] Rosenberg began his career at hometown club Malmö FF and became the Allsvenskan top scorer while on loan at Halmstads BK during the 2004 season.

Rosenberg's Allsvenskan success attracted interest from abroad, and ultimately he ended up playing for football clubs all across Europe, including Werder Bremen in the German Bundesliga, Ajax in the Eredivisie, Racing de Santander in La Liga, and West Bromwich in the English Premier League.

The following year, Rosenberg once again played a pivotal role in securing consecutive group stage qualifications for Malmö FF in the Champions League.

[15][16] On 2 July 2001, Rosenberg scored his first Malmö FF goal, in a 2–0 win against GIF Sundsvall,[17] However, he struggled to become a first-team regular with strong competition from Niklas Skoog and Peter Ijeh, resulting in him being placed on the substitute bench, as well as, his own injury concern.

[42][43][44][45][46] Rosenberg made his European debut in a 1–0 loss against Sporting CP in the second leg of the UEFA Cup first round, coming on as a substitute in the 62nd minute.

[48] When the club purchased strikers Afonso Alves and Igor Sypniewski ahead of the season, Rosenberg opted to go to Halmstads BK on loan in 2004.

[48][49] Rosenberg quickly made an impact on his Halmstads debut, scoring the club's third goal in a 5–2 win against Örebro in the opening game of the season.

[74][75][76] In his last match back in Malmö, he also topped the Royal League 2004–05 scoring list as well as leading Allsvenskan in assists before joining Dutch club Ajax.

[83] He quickly made an impact for Ajax, scoring on his debut, in a 2–2 draw against Brøndby in the first leg of the UEFA Champions League qualifying round.

[105] Playing in this line-up for the second half of the season, Ajax performed better and were able to reach the newly born Eredivisie play-offs after finishing in the fifth position in the regular competition.

[126] After adding only two goals in April in Bremen's fight for the Bundesliga title, Rosenberg scored his first hat-trick for the club in a 4–1 win over Hertha BSC on 6 May 2007.

[132][133][134] At the start of the 2007–08 season, Rosenberg's goal scoring form began to dip, leading to criticism from manager Thomas Schaaf, who was not satisfied with his performance in the club's pre–season tour.

[159][160][161][162] Despite a muscular injury sustained while on international duty, Rosenberg later added two more goals by end of 2008, scoring against Hertha BSC and Inter Milan (despite a 2–1 victory, Werder Bremen were eliminated from the group stage and demoted to the UEFA Cup).

[166] Despite being sidelined later in the 2008–09 season, he started in the 2009 UEFA Cup Final against Shakhtar Donetsk and played 78 minutes before being substituted, as Werder Bremen went on to lose 2–1 at extra time.

[169] By the end of the 2008–09 season, he had made 47 appearances scoring 13 times in all competitions, making him the club's third highest goal scorer, behind Claudio Pizarro and Diego.

[178][179] Following a poor performance in the Bundesliga against VfL Bochum, Rosenberg was not included in the squad for the subsequent semi-final match of the DFB-Pokal, against FC Augsburg.

[185] On the day Rosenberg signed a contract extension with Werder Bremen, he was loaned out to Spanish La Liga club Racing Santander for the rest of the 2010–11 season.

[254] On 3 February 2014, the transfer was confirmed after the medical examination had been performed, and Rosenberg subsequently travelled to Bradenton, Florida, where the club was engaged in a pre-season training camp.

[268][269][270][271] The following day, he scored a brace as Malmö FF defeated Red Bull Salzburg in a 3–0 win to qualify for the 2014–15 UEFA Champions League.

[288] Having been linked a move away from Malmö FF earlier in the season, Rosenberg put the transfer rumours aside when he signed a contract extension with the side, keeping him until 2017.

[298][299][300][301][302] One of the goals came in Malmö's 3–0 return leg win over Red Bull Salzburg in the third qualifying round for the 2015–16 UEFA Champions League on 5 August 2015.

[304][305] In their home match on 25 August 2015, Rosenberg scored the first goal as Malmö defeated Celtic 2–0, winning 4–3 on aggregate and thereby qualifying for the Champions League group stage for the second consecutive year.

[308][309][310] After serving a one-match suspension, Rosenberg returned to the starting line-up in the last game of the season against IFK Norrköping, only to be sent off in the 5th minute of the match, as Malmö lost 2–0.

[324][325] While serving a two-match suspension in the league, Rosenberg started in the Svenska Cupen Final against BK Häcken and scored the opening goal of the game before being substituted in the 64th minute, as Malmö FF lost 6–5 in a penalty shoot–out following a 2–2 draw.

[360] Two weeks later on 6 March 2018, Rosenberg reached a milestone in his Malmö FF career when he scored twice to add up his tally to 101 goals in his time at the club, in a 2–2 draw against FC Nordsjælland in a friendly match.

[390] Rosenberg, once again, helped Malmö FF advance past the 2019–20 UEFA Europa League group stages, having scored two more goals in the play–offs round.

[408] In the semi–finals against Serbia and Montenegro U21, Rosenberg was one of five Swedish players to successfully convert the shootout, as they lost 6–5 on penalties following a 1–1 draw through extra time.

[409] Three days later in the semi–finals against Portugal U21, he scored the national side's second goal of the game, as Sweden U21 lost 3–2 after extra time, thereby finishing fourth place in the tournament.

After a successful season in 2014, he was once again eyed by Sweden head coach Erik Hamrén, but chose to declare his retirement from international football to focus on his club career at Malmö FF.