Denver Broncos star Wes Welker said he enjoyed the novelty of remaining inconspicuous as his horse Undrafted made his Newmarket debut.
The 33-year-old wide receiver has played in three NFL Super Bowls, making him a recognisable figure in the USA.
Ridden by Frankie Dettori, Undrafted, who Welker bought for £29,000 in 2012, finished fourth in Saturday's July Cup.
"It's nice to just go to the betting window and not have to worry about taking selfies with people," he said.
"It's been fun. A beautiful place and a beautiful day," he told BBC Radio Cambridgeshire.
"The course is absolutely beautiful. It reminds me of a Saratoga or something like that."
Welker has played for the Miami Dolphins and New England Patriots, as well as the Broncos, and holds a host of reception records, including being the first man to register 100 receptions in five separate seasons.
Four-year-old gelding Undrafted has won four of his 15 races and is better suited to the turf, rather than the more common dirt tracks in the USA.
The weekend's fourth-place finish was his best Group One result to date.
"He's actually better on the turf. We finally found that six or seven furlongs on the turf and the hill at Newmarket fits him really well," said Welker.
"It was a great effort as he was up against great horses in this race. The sticky ground was not ideal for him but I was happy with the outcome."