Early life and career Ishak's parents were
Assyrian migrants from
Syria. He was born in
Södertälje, Sweden and started his professional career at
Assyriska FF, where he was included in the first team in 2010.
1. FC Köln In December 2011, Ishak was signed by German
Bundesliga club
1. FC Köln after a successful trial. He made his debut for the side on 21 January 2012 in a 1–0 away defeat at
VfL Wolfsburg, where he came on as a substitute in the 85th minute for
Martin Lanig. After being used mostly as a substitute during his first month in Köln, Ishak made his first start for the club on 18 March following a suspension for regular
striker Lukas Podolski, playing the entire match in a 4–1 away loss at
Hannover 96. Ishak would make 11 appearances for 1. FC Köln during his first season.
Loan to FC St. Gallen In February 2013, Ishak signed a six-month loan deal with Swiss club
FC St. Gallen, who had recently been promoted to the
Swiss Super League, in order to play more. He became a regular starter for the club, before suffering a
mandibular fracture in a match for the
Sweden under-21 team. Ishak made his return in late-April as a substitute in a match against
FC Zürich, before becoming a full-time starter again the following week. He made a total of 13 league appearances for St. Gallen, in which he scored three goals.
Loan to Crotone He was loaned out to
Crotone, competing in the
Serie B, following his arrival. He made his debut for Crotone on 24 August 2013 in a match against
Siena. On 24 September, he scored his first goal for the side in a 3–1 home win over
Modena.
Randers In August 2014, a year after joining Parma, Ishak moved to
Danish Superliga club
Randers FC, signing a three-year contract. He played for the club for two-and-a-half years, scoring 31 goals in 71 league appearances. He scored Nürnberg's 1000th goal in the 2. Bundesliga on 25 November 2017, in a match against
Eintracht Braunschweig. At the end of the
2017–18 season, he reached promotion to the
Bundesliga with the club. Ishak scored his first goal in the Bundesliga on 1 September 2018, an important equalizer in the away game against
Mainz 05, which ended 1–1.
Lech Poznań On 14 July 2020, Ishak joined Polish club
Lech Poznań on a
free transfer, signing a three-year contract. He was given the shirt number 9, previously worn by the outgoing Danish striker
Christian Gytkjær. In his first
season in Poland, despite missing over a dozen games due to health issues, he was Lech's top scorer with 20 goals, including two strikes against
Benfica and three goals against
Standard Liège in the
2020–21 UEFA Europa League group stage. Despite missing out on European competitions, the
2021–22 campaign was successful for both Lech and Ishak, who improved both health-wise and stats-wise. Named captain before the start of the season, the Swedish striker led Lech to their eighth
Ekstraklasa title, including a 88th-minute winner against
Piast Gliwice on 8 May 2022, which put Lech on top of the league table with two games to go. He finished the season with 18 league goals and was named the Ekstraklasa Forward of the Season. Ishak opened the
2022–23 campaign season by scoring the only goal in a
UEFA Champions League first qualifying round match against Azerbaijani side
Qarabağ on 5 July 2022. Although marred by health concerns throughout the season, he appeared in all but one of Lech's twenty games across their European campaign, scoring nine goals as the Poznań outfit reached the
UEFA Europa Conference League quarter-finals. In November 2022, he extended his deal until the end of June 2025, reportedly becoming the highest-earning player in Ekstraklasa at the time. With 20 goals to his name across all competitions, he was the club's best scorer for the third season in a row. On 13 April 2024, Ishak became Lech's top foreign scorer of all time, taking the title away from Gytkjær, after scoring his 66th goal in a 2–1 away loss against
Puszcza Niepołomice. Later that year, on 5 November, he signed a new contract, keeping him at the club until mid-2027. Throughout the
2024–25 season, Ishak scored 21 goals and provided five assists in 32 league appearances, as Lech took their ninth league title, Ishak's second as the club's captain. On 22 July 2025, Ishak scored his first hat-trick for Lech, converting three penalty kicks in a 7–1 win over Icelandic side
Breiðablik in the
UEFA Champions League second qualifying round. With 20 goals for Lech in Europe, he surpassed
Miroslav Radović as the best foreign scorer for Polish clubs in European competitions. On 20 September, he scored his 100th and 101st goals for Lech in a 2–0 league win against
Bruk-Bet Termalica Nieciecza. == International career ==