Walcott was deployed in a central attacking role for the FA Cup third-round tie against Spurs at the Emirates Stadium, but was carried off on a stretcher after jarring his knee when making a tackle during the closing stages - and subsequently pelted by objects thrown from the away end.
The Arsenal forward responded with "2-0" hand gesture in the direction of the 5,000-strong away section, as missiles, including coins and plastic bottles, were seen to hit medical staff as they carried the stretcher around to the tunnel on the half-way line.
The England forward's knee has been assessed by specialists, with the club set to examine those findings to determine a prognosis of just how long Walcott will be sidelined.
Walcott's absence, though, will not be down to any suspension, the Football Association confirmed on Monday afternoon.
The FA has taken in the full match report of referee Mark Clattenburg and will also speak to other relevant bodies before deciding whether to launch any disciplinary action regarding the crowd. It is understood Arsenal will provide CCTV footage to try to help identify any offenders from within the travelling support.
A statement read: "The FA has contacted both Arsenal and Tottenham Hotspur to seek their observations in relation to objects being thrown from both a home and away section of the crowd at different times during Saturday's FA Cup third round tie.
"The FA condemns any such acts and will liaise with both clubs and the Metropolitan Police to identify those responsible and support the strongest sanctions available, including life bans.
"Meanwhile, in relation to the same fixture, The FA has contacted Arsenal's Theo Walcott and reminded him of his responsibilities regarding a 'score-line' gesture he made in front of away supporters during the game. The FA will not be taking any further disciplinary action."
The loss of Walcott - who has scored five goals since returning from a stomach muscle injury - would further deplete Wenger's attacking options, given Nicklas Bendtner is expected to miss all of January with his ankle problem picked up when scoring a late goal in the 2-0 win over Cardiff on New Year's Day.
Should Walcott also be set for an extended spell on the sidelines, then Wenger concedes he will have to bolster the squad with some firepower, although continues to maintain a big-money signing during January is notoriously difficult to push through.
Wenger last week played down a move for Dimitar Berbatov, but the veteran Fulham forward would appear to fit the bill in terms of price-tag and experience.
Following their hectic festive schedule, Arsenal now have an extended break until the next Barclays Premier League match, when they travel to Aston Villa on Monday January 13.
Wenger has been impressed with the resilience of his squad, which has been tested again over Christmas.
"We had a very difficult schedule and we handled it very well, I would like to pay tribute to the players, they kept their focus during this period," Wenger said on Arsenal Player.
"You never felt that they wanted a breather, they will get one now, but they deserve it."
Wenger continued: "You feel the spirit is there to fight together.
"You can put any player anywhere, they just fight for each other and that is just the greatest ingredient of positiveness we have in the squad."
One player who epitomised that was teenager Serge Gnabry.
The 18-year-old midfielder impressed as he returned to the side against Spurs, where his determined run helped set up Santi Cazorla's opening goal.
Gunners vice-captain Mikel Areta has described the combative German as "like a little boxer", while Wenger is confident Arsenal youth product Gnabry has what it takes to make it at the highest level.
For now, though, Gnabry - who has a total of nine appearances this season, scoring his first senior goal in the Barclays Premier League win at Swansea - is taking things very much in his stride.
"It was great to have been given a start in such a big game, and I am satisfied with my performance," Gnabry said.
"I tried to have an impact going forwards and am happy that I could help the team to win with the assist for our first goal.
"I hope that I can show what I can do and that the team could need me, from then it is up to the manager."