The 21-year-old scored a hat-trick in the non-cap clash with Fiji at Thomond Park a fortnight ago before marking his Test debut with another superb try just 10 minutes into the game against Argentina.
And with selection now well and truly on Gatland's mind as the clock ticks down towards his squad announcement next spring, Gilroy's fine form has ensured he will be very much on the boss' radar over the coming months.
"Craig Gilroy was outstanding last weekend and he has put himself into contention. You aren't going to pick a Lions team based on that one performance, but he has put his hand up and made us sit up and take a bit of notice," said Gatland at an adidas shirt launch at Cardiff Castle.
"Nothing is crystallised at the moment. This far out from the tour you're looking at the players that have the form, reputation and pedigree, and seeing where they are at, and then looking at the youngsters who might not have been in the frame beforehand.
"You're looking at youngsters who put their hand up and make you go, 'Wow, that's pretty exciting'. He's definitely been one of those guys.
"He's definitely put himself in the frame. Now you watch him and say, 'Let's repeat those performances and let's continue to be that exciting'. From an Irish point of view, Keith Earls would have been one of those guys four years ago."
Gilroy is in one of the most competitive positions for Lions selection with clubmate Tommy Bowe, Edinburgh try machine Tim Visser, Welsh giants George North and Alex Cuthbert and English flyer Chris Ashton among the main contenders.
There's clearly much for Gatland to mull over before he picks his final party next April but the former Connacht, Ireland, Wasps, Waikato and now Wales coach insists he won't be leaving the planning process to the last minute.
"I sat down with some key personnel to look at what a pre-autumn squad would look like and I'll do that again post-autumn at the announcement of the other coaches," added Gatland.
"Then we will do a pre-Six Nations, middle-Six Nations and then post-Six Nations exercise before we pick the final squad."