Ajax will start its Champions League campaign against unbeaten Greek league winner PAOK Thessaloniki in the third qualifying round drawn Monday.
Last season, four-time European champion Ajax reached the semifinals in May having entered the competition in the second preliminary round in July.
As the Dutch league winner, Ajax now starts one qualifying round later - on Aug. 6 or 7, with the first leg in Greece - needing to beat two opponents instead of three to join the elite group stage.
Porto was paired with Krasnodar in a separate qualifying path for teams that placed second or third in higher-ranked leagues.
Also, Dynamo Kiev will face Club Brugge, and LASK will take on either PSV Eindhoven, the 1988 European champion, or Basel.
First-leg games are played Aug. 6-7, and return games on Aug. 13.
The second qualifying round is played through July 31.
(For more sports news and updates, follow Ahram Online Sports on Twitter at @AO_Sports and on Facebook at AhramOnlineSports.)