Elneny came into midfield alongside Granit Xhaka for the 2-0 win over Tony Pulis’ Baggies.
The Egyptian added steel to the Arsenal engine room, and allowed Aaron Ramsey to play further forward in support of Alexandre Lacazette.
Former Gunners star Keown was impressed, but admits Arsene Wenger's midfield still lacks the quality needed to shine at the top level.
“Xhaka looked short of confidence, I thought Elneny was the standout of the two (holding midfield players),” Keown said on Radio 5 Live.
“He came in and did very well.
“It is an area that concerns me - they don’t set the world alight and I don’t think they’ll frighten Europe those two.
“But Wenger believes in then, and they’ve got to believe in themselves.
“Elneny certainly did tonight, I thought there was a big improvement in his performance tonight.”
Keown was also full of praise for Lacazette, who he thinks will improve under Wenger.
The Gunners boss may ring the changes for Thursday’s trip to BATE Borisov in the Europa League.
Arsenal host Brighton in the Premier League at midday on Sunday and Wenger is likely to mix up his squad to deal with the quick turnaround.
