Coventry City manager Tony Mowbray says former Tottenham youth midfielder Ruben Lameiras may need to get physically stronger to cope with the demands of playing in League One.
Lameiras, 20, is on trial with the Sky Blues after leaving Spurs in March to join Swedish club Atvidabergs.
"He's got a good pedigree, he's a very technical and talented player," Mowbray told BBC Coventry & Warwickshire.
"The question's whether his physicality can cope with the division."
The Portuguese midfielder arrived at White Hart Lane in 2011, but failed to break into the first team in his near four-year stay in North London.
A regular in the youth sides, he scored one goal in eight games for Spurs' Under-21 side last season and Mowbray can see the attacking midfielder has potential - despite his diminutive frame.
"You can see what type of footballer he is - he's a technician and can play in tight areas," Mowbray said.
"But there are a lot of games in this league where it's very hurly-burly and 100 miles an hour - he's very slight but we're all impressed with his talent.
"If we did do anything with Ruben we'd have to pick our games. But there's no reason why he can't stay with us and we'll make a decision when we need to."
The Sky Blues, who finished 17th in League One last season, five points above the relegation zone, have signed three players ahead of the new campaign with Romain Vincelot,Chris Stokes and Sam Ricketts all arriving.