Michael Carrick may be set to face an awkward moment at the start of his permanent tenure as Manchester United manager.The new full-time Man United boss could have to omit defender Ayden Heaven from his Champions League squad this season.Heaven may have to miss out on the Champions League squad this seasonPACarrick led the Red Devils to an impressive third-place finish in the Premier League last term, turning things around after Ruben Amorim, who is now manager of AC Milan, was sacked in January.That meant they booked their place back amongst the elite in Europe for the first time since the 2023/24 campaign.But with that success may come an awkward decision for the United manager, if he pulls off one of his planned signings.As reported by talkSPORT earlier this month, Man United are interested in bringing in goalkeeper Karl Darlow. They are eyeing a new back-up to Senne Lammens, with Altay Bayindir set to leave the club this summer.Darlow impressed for Leeds last season, making 24 appearances in the Premier League after taking the No.1 shirt of Lucas Perri.And not only that, but he’s also an attractive prospect to add to the squad to help them reach homegrown requirements.A homegrown player is someone who has been registered with a club affiliated to The Football Association or the Football Association of Wales for three seasons or 36 months, before turning 21.All top-flight clubs need at least eight homegrown stars in their 25-man squads, with Darlow helping United achieve that.But as a knock-on effect, Heaven could be left out…Man United are eyeing Darlow as another potential homegrown player in the squadGettyHeaven has impressed when starting for the Red Devils since his move from ArsenalAlamyHeaven or hell?The 19-year-old centre-back has made 24 appearances for Man United since joining from Arsenal in 2025.Of those 24 appearances, 17 have come in the Premier League. He has never played a match in the Champions League.Heaven may have hoped that his first game in the competition would come this campaign, having impressed when covering for injury-hampered Harry Maguire, Matthijs De Ligt and Lisandro Martinez.However, rules could cruelly prevent him from featuring. UEFA state that clubs can have 17 players who have been nurtured outside of their association in their 25-man squads.Within the other eight places, teams can have up to four trained at clubs other than the one they play for currently and four that have come through the club’s academy and are over 21.UEFA rules may force Carrick to make a tough decision on his squadGettyHeaven didn’t come through Man United’s academy, although he has not yet been a Red Devils player for two years, which means he does not count as being nurtured by the association yet.On the other hand, Darlow would match the requirements to be a homegrown player, helping United stick to the UEFA ruling.But then, if Darlow were to sign and be named in the Champions League squad by Carrick, he may have to leave someone out. And Heaven could be the one snubbed, as he could only be registered as one of the 17 who came through at another club.The Red Devils didn’t have to deal with UEFA registration rules last season as they didn’t play in Europe.However, now they’re in the Champions League, it means a few more complicated decisions are coming Carrick’s way.