Good signing from Carlisle United-eh
Senior spent nearly a decade with Oldham Athletic, but was released at the age of 15 for being too small.[3] He later described it was the worst day of his life.[3] He began playing non-league football around Greater Manchester, initially with Sunday league team Hough End.[3] At the age of 16 he was playing for Maine Road and working two days a week in an engineering and design company.[3] He then made 68 appearances in all competitions for F.C. United of Manchester,[4] including 58 league appearances,[5] before moving to Curzon Ashton in February 2019,[6] for whom he made ten league appearances in National League North.[5]
In May 2019 he signed a 12-month contract with Premier League club Burnley, with the option of a further year, with the intention that he would initially play with their under-23 team.[3][7][8]
He was released by Burnley at the end of the 2019–20 season.[9] He later signed for Altrincham.[10] He signed for Carlisle United in January 2022.[11]
On 30 May 2023, after Carlisle won promotion to League One, Carlisle manager Paul Simpson announced that Senior would be released once his contract expired. One key reason was the emergence of fellow right back Jack Ellis.[12]