Celtic reportedly sent scouts to watch Benfica take on Moreirense this weekend.
Celtic remained on top of the Scottish Premiership this weekend, with John Guidetti's second half goal handing them a narrow 2-1 win over Dundee at Celtic Park.
Yet whilst that was going on, manager Ronny Deila had dispatched his scouts off to Portugal in order to watch Benfica's cup tie with Moreirense.
It's an interesting scouting mission for Celtic, considering that many of Benfica's star players have been linked with moves to Chelsea or Manchester United, but this game was of particular interest to Celtic.
Given that it was a cup tie, Benfica chose to rest some of their key players, and handed some first-team football to some of their more fringe prospects.
Loan deals could be in Benfica's interest in January, and Deila will have sent his scouts to watch and see if any of them would be good additions for Celtic.
Three players stand out from those that featured for Benfica, and the first is left back Loris Benito. The Swiss youngster has barely featured as a backup to Eliseu, and with the more experienced Silvio also capable of playing at left back, the Portuguese giants may be willing to loan Benito out - and he could compete with Emilio Izaguirre at Celtic, with fans wanting another left back to arrive in January.
Winger Ola John only came on at half time for Benfica, and he'd be quite the coup for Celtic. The pacey Dutchman was linked with Liverpool last season, and has yet to make a league start for Jorge Jesus' side this season, having to settle for substitute appearances.
Celtic don't necessarily need a winger, but with chaos over Aleksandar Tonev's future, Mubarak Wakaso only on loan from Rubin Kazan and Kris Commons linked with a move back to England, it's a situation that could develop in the New Year for Deila.
Finally, striker Derley has started just once since joining from Maritimo this season, with Jesus preferring to use Lima, Anderson Talisca and Jonas in attack. The 26-year-old Brazilian impressed with Maritimo a year ago, and if Celtic lose Guidetti in January, they'll need another striker to replace him - and Derley could be on their radar after playing 90 minutes against Moreirense.
It's unclear who Celtic were specifically scouting - they may have just been watching a top side at work - but if they were at the Estadio Da Luz for new signings, these three players figure to be the most likely to make temporary moves to Glasgow in January.