Tottenham wing-back Danny Rose will see a specialist on Monday in relation to the knee injury he suffered during the 0-0 Premier League draw at Sunderland.
Rose has been one of many impressive performers for Mauricio Pochettino's second-place side this season, but reports in the aftermath of Tuesday's stalemate at the Stadium of Light suggested he could face around a month on the sidelines with medial ligament damage.
The England international underwent a scan and it has been deemed further attention is necessary.
"Danny Rose had a scan yesterday [Thursday] and now we need to wait until Monday to see the specialist," Pochettino told a news conference previewing Saturday's match against Middlesbrough.
Captain Hugo Lloris is set to return in goal after overcoming a bout of illness, although Jan Vertonghen (ankle), Kieran Tripper and Erik Lamela (both hip) remain sidelined as Spurs aim to return to winning ways in the top flight following back-to-back draws.
Leaders Chelsea entertain Arsenal in Saturday's early kick-off, with Tottenham's north-London rivals level on points with them in third.
Pochettino does not wish to become distracted by that blockbuster clash and lamented his players' failure to capitalise on Antonio Conte's men drawing 1-1 at Liverpool in midweek.
"I think the most important thing, obviously, is us," he said. "Look at what happened against Sunderland.
"That was a big opportunity to close the gap and we were not capable to win.
"For me, we must always focus on us and show we deserve to win the game and get three points. Then we think about what happens in other stadiums.
"We missed a big opportunity to reduce the gap."
Asked whether he would draw a temporary truce in the Spurs-Arsenal rivalry and want Arsene Wenger's side to prevail at Stamford Bridge, Pochettino replied: "No… I don't care."