The France youth international is Arsene Wenger's only signing so far this summer and the forward is impressed by his new team-mate's early promise at the Emirates Stadium
The France youth international is the Gunners' only signing so far this summer and played an hour in the pre-season Emirates Cup match before being replaced by Olivier Giroud.
Walcott is impressed by the early promise shown by Sanogo, who nearly opened his account for Arsenal in the first minute, and hopes he is afforded chances despite the competition for places.
“There's a lot of competition for that position but I think he showed his qualities in patches today definitely," he told the club’s official website.
"He's a strong boy. He's only had a couple of training sessions with us. I've only trained with him a couple of times. He's a nice lad and I think he'll do very well for us."
Two second-half goals from Didier Drogba saw Galatasaray snatch a late victory, and the Emirates Cup, but Walcott believes his side can take heart from their performance as the test will serve them well heading into the new season.
"It was disappointing in the end," the 24-year-old commented. "I felt like we dropped off. But they showed their class with Wesley Sneijder and Didier Drogba coming on at half-time. It showed a bit of a different presence for Galatasaray.
"I think you've got to take a lot of positives out of the game. It's good fitness work as well and that's the whole point of it all. Come the start of the season, we'll be ready.
"We've got another couple of weeks of training before the start of the season and everyone will be sharp - trust me. It's a big wait."