Pedzisa mutsara unotevera: Nekuda kwe2012 / 13 NHL lockout, Gunnarsson akaburitswa neLeafs kuitira kuti atambe mwaka pamwe nechikwata chake chekumusha Örebro HK. Mushure mekuvharirwa kwapera, Gunnarsson akadzokera kuNorth America ndokuenderera mberi nemwaka neToronto Maple Leafs. Zvisinei, nguva yake mumutsara yakange iri pfupi sezvo aiita kurapwa kuti agadzirise kukuvara kwechiuno mushure mekutamba mumitambo minomwe. Gunnarsson akabvumidzwa kutamba Leafs isati yatanga mwaka wa2013-14 uye akaita mutsara wavo wekutanga. Mwaka iwoyo waizova wekupedzisira neMaple Leafs, sezvo musi wa 28 Chikumi 2014, Gunnarsson uye wechina-kutenderera dhizaini mu
2014 NHL Entry Draft vakatengeswa kuSt. Louis Blues mukutsinhana nemudziviriri Roman Polák. Akavhiyiwa muhudyu panguva yemwaka uye akaburitswa zvokurapa kuti atambe musi wa14 Gumiguru 2014.