The former Liverpool defender also doesn't see any new faces arriving at Anfield in the rest of the window.
The Reds secured the signing of the Brazilian from Hoffenheim in July, and he has arrived at Anfield with a big weight of expectation upon his shoulders.
He is one of several arrivals at the club this summer as Brendan Rodgers has spent big money to reinvigorate his squad after a disappointing sixth place finish in the Premier League last season.
More than anything they were lacking in options last season, and Thompson says the signing of Firmino gives them just that next year.
“I think Firmino will be that attacking player to excite the crowd and get the goals from midfield,” he told Sky Sports.
"Sterling could play in quite a few positions, but Firmino now gives them that option. From what we know he has the ability to play wide, good ability to beat people (and has) assists and goals in his play from midfield. It gives Brendan options to be flexible with his squad."
No more signings at Anfield now
The big worry for Liverpool of course is how the number of new signings all gel together into a team next season.
The Reds were equally busy last summer with a whole host of new faces arriving at the club, although most of those proved to be poor purchases with only Emre Can having been considered a success.
Thompson is pleased though despite the similarity to last summer, saying some of the individuals were sought after, although he doesn’t expect any new arrivals with a month of the window left.
“Some of the individuals we signed were very good, well sought-after, and it's the same again this summer,” he added.
"But I don't think there are going to be anymore signings. I would be massively surprised if we bring anyone else in."