Inter Milan director of football Piero Ausilio was at Old Trafford on Wednesday night watching a player from each side.
The San Siro boss was keeping a close eye on Manchester United striker Romelu Lukaku and Barcelona's Ivan Rakitic.
Inter are considering their position this summer and may splash the cash as they look to rein in runaway leaders Juventus next season.
The ambitious Italians have already draw up a short list of possible new signings.
Ausilio also took into Tottenham's 1-0 victory over Manchester City - and this time went with the intention of looking at three players.
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Spurs duo Christian Eriksen and Serge Aurier are both considerations, while City's Ilkay Gundogan is well liked by Inter.
The five-man, two-day scouting mission was to keep tabs all the players according to Sport Witness .
While their chances of luring Eriksen to Milan are slim, Lukaku's form for United has been erratic since signing with a £75million price-tag he has failed to offer value for money for.
Manager Ole Gunnar Solskjaer says United are still very much in the tie despite heading to Barcelona needing to produce another Champions League escape act.
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“We are Manchester United - you can never write us off,” he said after the 1-0 home defeat.
“I thought in the first ten minutes, we showed them too much respect. After that we adapted really well and started to take control of the game and looked the better side. Unfortunately we didn’t get a goal.
“We need to score more goals and be more together as a group. We’ve got a big second leg to come and it’s only half-time.”
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Former right-back Gary Neville isn't quite as convinced.
He believes Manchester United only have a five to ten percent chance of overturning Barcelona's lead in the quarter-finals.
"It's going to be difficult, it's a one in ten chance, one in 20 chance that we'll go there and win 2-0 or 3-1 or whatever it is we need," he said.
