The Baggies yesterday snapped up former England striker Andy Carroll on a short-term deal until the end of the season.
It had been hoped Dike would be the man to end their problems in front of goal.
But the American pulled his hamstring 50 minutes into his full debut and is now set to be sidelined for the next eight weeks.
And following that injury, Ismael felt it was imperative Albion re-entered the market this month to sign Carroll.
“In the short-term it is someone able to help us,” Ismael said. “Someone to have that impact.
“We saw in Dike’s first start against Peterborough he played 50 minutes and had five chances to score. You see how important it was to get that target man in the box.
“I think with Andy we have that.
“He has the experience and that can help us to get the power we need in the opponent’s box.
“He is a number nine and this is the reason he is here, to score goals and to have an impact on the opponent’s defensive line.
“He will have an impact on the front three, impact in the opponent’s box, link-up, he has desire and leadership.”
Albion have struggled for goals throughout the 2021/22 campaign – scoring just once in the first half of their last 15 league matches.
Jordan Hugill was signed on loan from Norwich in the summer but he has failed to have the desired impact at the club, scoring just one goal in 20 appearances.
He is expected to leave the club this month with Norwich currently working to try and find him another Championship loan – with Hull having been linked with a move for the former West Ham man.
Matt Phillips and Callum Robinson have been deployed as central strikers – but both are more effective when playing out wide.
And the injury to Dike left Albion short of numbers up front ahead of the transfer window’s closure on Monday.
“In January it is not always easy to find the player,” Ismael continued when asked about his hunt for a new striker.
“We found it with Dike and then we got the injury situation.
“We followed Andy’s performances with Reading, he has that hunger and desire.”
Carroll, who once cost Liverpool £30million, left boyhood club Newcastle at the end of the last season.
He was without a club until November when he joined Reading.
The 33-year-old impressed in eight outings for the club – with one of those appearances coming against Albion last month.
And Ismael revealed the former England striker caught his eye during that game at The Hawthorns.
“He scored goals for Reading and we played against him so it was easy to assess him,” the boss said.
“He had an impact so our expectation now with him is that he will score goals.
“With the quality we have in the squad – and the crosses we put in during a game – we hope he is able to finish the job.
“The fact Andy has played plenty of games for Reading recently is great. He’s fit and he has that hunger and desire.
“When I spoke with him I felt it straight away.”