Wings Josh Adams and George North will play centres for their regions as Wales aim to find somebody to wear the number 13 jersey in the Six Nations.
Adams will play centre in the Challenge Cup match against Leicester, while North lines up in the Ospreys midfield for the Champions Cup match against Saracens.
New Wales coach Wayne Pivac is looking for someone to partner Hadleigh Parkes.
Wales play Italy on 1 February and face Ireland seven days later.
British and Irish Lions centre Jonathan Davies will miss the Six Nations tournament because of a knee injury and Owen Watkin is absent for at least the opening two games.
Watkin had partnered Parkes in Wales' midfield in the Barbarians match.
The 23-year-old will miss the start of the 2020 Six Nations following knee surgery after limping off during Ospreys' 40-19 loss to Racing 92 on 7 December and is expected to be out until the middle of February.
North, 27, has started four of his 91 Test matches for Wales in the centre.
Adams played the final moments of Wales' uncapped 43-33 win over Barbarians in the centre in November 2019 which was Pivac's first game in charge.
The 24-year-old has scored 11 tries in 21 internationals for Wales since making his debut in 2018 and was the 2019 World Cup top try scorer with seven.
Adams joined Cardiff Blues from Worcester for the 2019-20 season and has scored four tries in five appearances.
Cardiff Blues centre Willis Halaholo was in Pivac's first squad against Barbarians after qualifying through residency but he has been ruled out for the rest of the season with a knee injury.
Scott Williams, Jamie Roberts and Tyler Morgan are established alternatives Pivac could consider. Williams is currently sidelined with a hamstring injury.
Scarlets centre Steff Hughes has been impressive for his region this season, while less experienced options could include Cardiff Blues centre Ben Thomas and Ospreys' Tiaan Thomas-Wheeler.