Manfredi played his junior rugby at Leigh Miners Rangers until he was 14 and joined the Wigan club where he progressed well through the scholarship and academy set up.
Signing for Wigan, Manfredi spent a period on loan with Championship 1 team South Wales Scorpions before making his Super League début against Hull FC on 3 August 2013, in a 33–34 defeat at the DW Stadium.
The following season, 2014, Manfredi made 14 appearances for Wigan scoring 11 tries as well periods playing for Super League rivals, Salford, and (then) Championship team, Workington.
[5] At the start of the 2016 season he was given the number 5 jersey for Wigan after the departure of Joe Burgess to the NRL, and went on the score 15 tries in 25 appearances as well as three Man of the Match awards.
His season was cut short in August due to an anterior cruciate ligament injury in a tackle by Rangi Chase against Castleford Tigers.