Ramba uchinyora ndima ino - Pamakwikwi eOlympic yeZhizha ya2004 muAthens, Alleyne akachengeta purogiramu yake kupfurikidza nokukodzera mumitambo miviri yokushambira. Akabvisa FINA B-standard yekupinda nguva ye51.89 (100 m freestyle) uye 1:53.19 (200 m freestyle) kubva kuPan American Games muSanto Domingo, Dominican Republic. Mumakwikwi emamita mazana maviri akasununguka, Alleyne akatarisana nevamwe vanoshambira vanomwe pakupisa kwechitatu, kusanganisira vamwe vake vakambokunda maOlympic Joshua Ilika Brenner wekuMexico naGiancarlo Zolezzi wekuChile. Akapfuura Algeria's Mahrez Mebarek kutora nzvimbo yechitatu uye makumi matatu nemana pakupedzisira ne0.11 yechipiri mu1:52.89. Muchiitiko chake chechipiri, 100 m freestyle
, Alleyne akaiswa pachinhanho chemakumi mana nesere mumakwikwi okutanga mangwanani. Achishambira mumakwikwi matatu, Alleyne akaenzanisa nguva yake yekupinda ye51.89 kuchengetedza nzvimbo yechishanu pamusoro peZolezzi's compatriot Max Schnettler ne0.02 yechipiri.