Estonia

Nieminen was also briefly an assistant manager of TPS, before he moved to Estonia in 2014 to coach the goalkeepers of the Estonian youth national teams, as a goalkeeping coordinator of Estonian FA.^[4]

Aspire Academy

In February 2015, Nieminen was appointed the goalkeeping coach of Qatari Aspire Academy with fellow Finnish coach Jarkko Tuomisto, and the Qatar under-17 national team, where he specialized in elite player development and game analysis.^[5]

San Jose Earthquakes

After three years in Qatar, Nieminen was appointed the goalkeeping coach of Major League Soccer side San Jose Earthquakes on 25 January 2018.^[6][7][8]

Orlando Pirates

In July 2019, Nieminen signed with South African giants Orlando Pirates.^[9] After approximately a year-and-a-half with the club, Nieminen announced his departure in late December 2020.^[10][11]

New York Red Bulls

Nieminen returned to United States and MLS, when he was appointed the goalkeeping coach of New York Red Bulls in early 2021.^[12][13]

On 6 July 2023, the club announced that they had reached an agreement with Feyenoord on the fee for his contract, and he will depart the club.^[14] In all three seasons Nieminen was in New York, the club ranked in top 5 in MLS with the least goals allowed in the league.

Feyenoord

In July 2023, Nieminen was appointed the goalkeeping coach of Dutch champions Feyenoord on a three-year deal.^{[15][16][17][18][19][20]}