Manchester United's youngsters fell to shock 2-1 defeat away to Kazakhstan side Astana in their Europa League clash on Thursday.
Manchester United players have been told not to go outside for more than 10 minutes at a time when they travel to Astana, due to cold conditions.
Mason Greenwood scored his first senior goal for Manchester United in a 1-0 win over Astana in Europa League Group L at Old Trafford on Thursday.
Celtic progressed into the Champions League but the 4-3 second-leg loss in Astana was their first of the season although they won 8-4 on aggregate.
Celtic put one foot into the Champions League group stages with a 5-0 thumping of Astana in the first leg of their playoff at Parkhead.
Manchester United's troubles away from home in Europe continued in a 2-1 defeat at Fenerbahce in the Europa League as Paul Pogba limped off injured.
Manchester United laboured to a 1-0 Europa League victory over Zorya Luhansk at Old Trafford as Zlatan Ibrahimovic headed home in the second half.
Brendan Rodgers called for Celtic fans to trust his players after it took Moussa Dembele's dramatic stoppage-time penalty to give the Hoops a 2-1 win.
Moussa Dembele's first Celtic goal gave the Hoops a dramatic last-gasp 2-1 win over Astana and booked them a place in the Champions League playoff.
Leigh Griffiths' 78th minute strike gave Celtic a 1-1 draw against FC Astana and put the Hoops firmly in charge of their Champions League destiny.
Celtic put part-time Lincoln Red Imps in their place with a 3-0 Parkhead win that set up a Champions League third-round qualifying match with Astana.
FC Copenhagen cruised to a 3-0 win over Northern Ireland side Crusaders in the first leg of their Champions League second qualifying round.
Galatasaray secured themselves a Europa League spot with a 1-1 Champions League Group C draw against Astana.
Raul Jimenez scored twice as Benfica fought back from two goals down to draw 2-2 with FC Astana.
Atletico Madrid were stymied in Kazakhstan as they settled for a goalless draw against FC Astana in the Champions League on Tuesday.
"Tomorrow's match is the determining factor for our team future because all teams find it difficult to win on this pitch," said Simeone of Astana.
Atletico Madrid brushed aside Astana 4-0 on Wednesday evening to return to winning ways at the Vicente Calderon stadium in the Champions League.
Benfica opened their Champions League campaign with a 2-0 victory over group stage new boys Astana in Lisbon.
FC Astana are a tiny, new club, but they are backed by Kazakhstan's vast resources. Nick Ames went to see their grand project up close.
Manchester City have been handed a tough Champions League group stage draw against Juventus, Sevilla and Borussia Monchengladbach.