He signed his first professional contract with Bournemouth in 2018.[2] In January 2019, he was loaned to Scottish Championship club Dundee United until the end of the 2018–19 season.[4] He made his debut in a 1–0 defeat against Ayr United.[5]
Seaman was on trial with EFL League Two club Exeter City in July 2019, playing in a pre-season friendly against Taunton Town.[6] In September 2019, Bournemouth loaned him to Eastleigh in the National League until the following January.[7] After making 24 appearances for Eastleigh, he returned to Bournemouth having been ruled out for the next three months with a hamstring injury.[8] Seaman went on loan again at the end of the January 2020 transfer window, joining Maidstone United in National League South until the end of the 2019–20 season.[9] They were willing to sign him while he was still recovering from injury, as it was at no cost to the club.[10] He made his Maidstone debut as a substitute against Eastbourne Borough on 14 March,[11] just prior to football being suspended due to the coronavirus pandemic.[12]
Seaman was released by Bournemouth at the end of his contract in June 2020.[13] On 1 October 2020, he joined League One club Doncaster Rovers on a one-year contract and was subsequently loaned out to Maidstone United.[14] He returned to Doncaster for the remainder of the 2020–21 season as the regional National League season at Maidstone was cancelled.[15]
On 27 July 2023, Seaman joined National League side Hartlepool United on a season-long loan.[16] On 5 January 2024, his loan spell was terminated by mutual consent after Seaman had made 16 appearances and scored twice for Hartlepool.[17] On 19 January 2024, he signed for National League side Wealdstone until the end of the 2023–24 season.[18]
On 15 May 2024, Doncaster announced he would be released in the summer when his contract expired.[19]
On 4 June 2024, Seaman returned to Maidstone United on a permanent basis having had two previous loan spells with the club.[20]