Day of Reckoning, on 11 October 2008, the event was rescheduled and Arlovski would instead be matched up against the last reigning IFL Heavyweight Champion Roy Nelson at EliteXC: Heat on 4 October 2008, in Sunrise, Florida in a co-promotion with EliteXC. Arlovski won the fight via KO in the second round and in the process became the only man to ever finish Nelson in his MMA career at that point. In January 2009, Arlovski faced the last reigning PRIDE heavyweight champion Fedor Emelianenko at Affliction: Day of Reckoning. Arlovski lost the fight via KO in the first round. Strikeforce On 6 June 2009, Arlovski fought up and coming heavyweight Brett Rogers at Strikeforce: Lawler vs. Shields. Arlovski lost the fight via TKO in the opening round. After the defeat, in October 2009, Arlovski began training with acclaimed MMA coach Greg Jackson. Arlovski was a featured attendee at Strikeforce: Emelianenko vs. Rogers, where he was mobbed by a crowd of local Chicago fans. Arlovski was signed to Strikeforce and fought former EliteXC heavyweight champion Antônio Silva on 15 May 2010, at Strikeforce: Heavy Artillery. Following 3 rounds of hard-hitting punches from both and with neither fighter giving in to the other, Arlovski lost by unanimous decision. Arlovski was defeated by Sergei Kharitonov via KO on 12 February 2011, as part of the Strikeforce Heavyweight Grand Prix Tournament. It was his fourth straight loss, three of which were by way of KO. On 17 February 2011, Arlovski posted a video on his website in which he spoke for over an hour, repeatedly saying that he would absolutely not retire. Arlovski indicated that his trainers had recommended that he retire; however, Greg Jackson was against his retirement. Arlovski dedicated himself to training exclusively with Greg Jackson in New Mexico to refocus on his MMA career and make the necessary changes to get back on track. ProElite After several months of grueling training schedule in New Mexico with Greg Jackson and the likes of Jon Jones, Shane Carwin, and Travis Browne, Arlovski headlined ProElite 1 on 27 August at the Neal S. Blaisdell Center in Honolulu, Hawaii against heavyweight Ray Lopez. Arlovski won by TKO in the third round after dominating Lopez throughout the fight. Arlovski faced off against veteran of over 300 fights Travis Fulton at ProElite 2 in November, serving as the co-main event. Arlovski won the fight via head kick