Lewis pulled up early in the game holding his hamstring, and was replaced by Matt Ritchie.
The left-back – who had come into the team when Ritchie was suspended last month – is now being assessed ahead of the club’s bust festive programme.
“It looks bad – it looks like a hamstring problem,” said head coach Eddie Howe. “It’s a surprise with Jamal, because he’s obviously so athletic. He’s been excellent in terms of his athletic work for us.
“Obviously, it was damaging to lose a sub so early in the match. I thought Matt Ritchie came on and was fantastic in his place. Certainly, it’s not the time of year for us to lose players. Fingers crossed, it’s only Jamal that will probably go into the Christmas period now in any doubt, but we need to check on a few others that were carrying things.”

1. Toffees target Centonze
Everton are reportedly lining up a move to sign Fabien Centonze from French club FC Metz in the upcoming January transfer window. (Football Insider) (Photo by SYLVAIN THOMAS/AFP via Getty Images) | AFP via Getty Images

2. Chelsea want Martinez
Chelsea want to sign Lautaro Martinez from Inter Milan and reunite him with former Inter Milan strike partner Romelu Lukaku. (Fichajes) (Photo by Marco Luzzani/Getty Images) | Getty Images

3. Spurs and West Ham keen on Milenkovic
Tottenham are ‘ready to enter' into negotiations to sign Nikola Milenkovic, who West Ham also want. (Corriere di Puglia e Lucania) (Photo by Gabriele Maltinti/Getty Images) | Getty Images

4. West Ham eye cut price Tarkowski deal
West Ham could make an offer in the region of £4million to sign Burnley defender James Tarkowski in January. (Claret and Hugh) (Photo by Stu Forster/Getty Images) | Getty Images