DePaul Lieutenant DePaul was a male Human Starfleet officer who lived during the mid - 23rd century . He served in the command division aboard the under Captain James T . Kirk , during a historic five - year mission that starship undertook . He served as both a relief navigator and a relief helmsman . ( ) Appendices . Background information . Lieutenant DePaul was played by Sean Kenney , who also portrayed the disfigured Christopher Pike in and . On the final day of the two - parter ' s production shoot , Gene Roddenberry approached Kenney and , much to the actor ' s surprise , offered him the re - occurring role of Lieutenant DePaul . " " That ' s when Lt . DePaul was born , " " noted Kenney . Roddenberry ' s offer of the role was because he wanted to thank Kenney for how he had played Pike , having dealt with a lot of makeup . ( " Captain Pike Found Alive ! " , " Chapter Three : The Formula " ) About a month thereafter , Sean Kenney found himself back on the Paramount lot , to portray Lieutenant DePaul in " Arena " . ( ) The performer was extremely relieved by the differences between this role and his earlier part on " Star Trek " . " " It was a real treat , " " he reminisced , regarding the experience of personifying DePaul . " " I could speak , I had lines ! " " ( " Captain Pike Found Alive ! " , " Chapter Three : The Formula " ) Kenney was also pleased he was able to play DePaul while having his own natural dark hair ( whereas his hair had been dyed for depicting Pike ) and that he didn ' t have to wear restrictive makeup which prevented him from speaking to other people . Because he had had to don such intensive makeup for playing Pike , few people knew DePaul wasn ' t the actor ' s first " Star Trek " role . ( " " , issue # 113 ) " " So , doing ' Arena ' , " " recalled Kenney , " " it was like my first time on set . " " McCoy actor DeForest Kelley , at one point , became interested in trying to figure out how Kenney had obtained the part and , years later , Kenney joked he would never forget Kelley staring at him . " " I ' m sure De was thinking I was a little young for the part , " " Kenney clarified . Kelley asked about the specifics of Kenney ' s casting as DePaul and was flabbergasted when one of the men from the makeup department revealed Kenney had been Pike . ( ) DePaul ' s reappearance as the relief helmsman in " A Taste of Armageddon " came about because Sulu actor George Takei was on temporary leave from , filming the movie " The Green Berets " . ( ; " Captain Pike Found Alive ! " , " Chapter Three : The Formula " ) Sean Kenney very much enjoyed returning to work as DePaul in " A Taste of Armaggedon " , in which he felt he had " a little higher profile " than in the other " Star Trek " episodes he participated in . He recounted , " " I said , ' Wow , I ' m just going upward on this show . ' That was a great opportunity . " " ( ) Kenney was initially unaware , however , that the helmsman ' s controls were dangerous , which he referred to as " the one thing Takei didn ' t tell me before he left . " ( " Captain Pike Found Alive ! " , " Chapter Three : The Formula " ) " " When I sat at the console and pressed the plastic buttons , " " the actor explained , " " sometimes they would get so hot my fingers would [ burn and ] stick - to the melting plastic . This was before the days of low - voltage bulbs . I couldn ' t yell out – I would just have to pull my fingers off as quickly as I could and hope the camera didn ' t pick it up . " " ( " " , issue # 113 ) The pain caused to Kenney ' s fingers was evident by the end of the first day of shooting " A Taste of Armageddon " . " " I went home the first night and laid them in a pack of crushed ice , " " he said . " " Once burned , never again . " " ( " Captain Pike Found Alive ! " , " Chapter Three : The Formula " ) Despite the discomfort of operating the helm station , Sean Kenney relaxed into his task of reappearing as DePaul in " A Taste of Armageddon " . " " I had no idea it ' d be my last time on the show , " " he noted . ( ) Just when Kenney felt everything was going smoothly , Gene Roddenberry confessed to him that DePaul was to be replaced with a new Russian character , which eventually turned out to be Chekov . Kenney considered the replacement " a great favor . " " " Thankfully I got out early , " " he related , " " because many felt that the actors in " Star Trek " became household faces and their careers ended by being too type cast [ . . . ] I ' ve had no regrets leaving the original series . " " ( " Captain Pike Found Alive ! " , " Chapter Four : Kicked Upstairs " ) The revised final draft script for " A Taste of Armageddon " called him Cheffski . Following the production of " A Taste of Armageddon " , however , DePaul was written into the first draft script of ultimately undeveloped episode " " ( dated ) . In that installment , he was intended to have dialogue and appear in multiple scenes . DePaul was given the first name Sean in " " .