The Scot was one of the busiest managers during the summer transfer window after taking over the Latics hot-seat from Roberto Martinez, signing 12 players either permanently or on loan.
But Coyle believes he needs more numbers to cope with the demands of at least six Europa League games on top of a hectic Championship programme and domestic cup matches.
The Latics boss is trying to bring in more players on loan, while he already has his sights on the January market, where he will attempt to spend some of the £13million Everton paid for midfielder James McCarthy on deadline day.
Coyle said: "It didn't allow us any time to spend that money. We worked very hard at wheeling and dealing before that, we probably still had a surplus of £1million from Arouna Kone and (Mauro) Boselli, and James' deal has added to that.
"We're sitting there with money to spend. I've tried to spend it, even in this loan window. You can understand a lot of clubs are not wanting to part with their best players.
"There's no secret that we'd love to add a striker to our array of talent given the injuries to (Grant) Holt and (Marc-Antoine) Fortune. It's not come to fruition yet but it won't stop us persevering and trying to use that loan market."
The DW Stadium will host European football for the first time on Thursday as Wigan take on Slovenian side Maribor.
The FA Cup winners are bidding for a first victory in continental competition following their goalless draw against Zulte Waregem in Belgium a fortnight ago.
Coyle added: "Hopefully it will be a special atmosphere. Coming along for the first home European tie, it will be a special night for everybody."