Liverpool and Tottenham Hotspur were among several teams who had scouts present at Benfica's 2-0 win over Famalicao last Friday, with both keeping watchful eyes over Antonio Silva and Florentino Luis, sources have told 90min.
The Eagles moved eight points clear atop the Primeira Liga table and have enjoyed a superb season, with a number of talented youngsters playing pivotal roles.
Among those have been centre-back Silva and midfielder Luis, and 90min understands that they are of interest to Liverpool and Tottenham.
19-year-old Silva is enjoying a fine breakout campaign for Benfica, already featuring 31 times in all competitions during his first season in the senior setup.
Silva's impressive form so early into his career led to him earning a place in Portugal's squad for the 2022 FIFA World Cup, becoming the youngest player to represent the Selecao on such a stage when he started in their dead rubber group stage match against South Korea.
With Silva playing most of their games at the heart of defence, Benfica have conceded just 13 goals in 23 league games this season.
Luis, meanwhile, is enjoying a resurgence having spent the last two seasons out on loan at Monaco and Getafe respectively.
The 23-year-old defensive midfielder was named in Portugal's preliminary squad for the World Cup, but unlike Silva did not make the final cut.
Star striker Goncalo Ramos scored the match-winning brace against Famalicao and is admired by plenty of big-hitters across Europe, but it's believed the purpose of Liverpool and Spurs' scouting missions were specifically to watch Silva and Luis.
Benfica are well-positioned to progress further than both Liverpool and Tottenham in this season's Champions League - they lead Club Brugge 2-0 in their last 16 tie, with the second leg coming at home to the Estadio da Luz.
They also notably topped a tough group which featured Paris Saint-Germain and Juventus.