The Alex boss was impressed with the attitude of Republic of Ireland U21 striker Walters during his month's stint at Gresty Road and has said he hoped to keep the former Blackburn Rovers Academy player a while longer but due to Bolton loaning Delroy Facey to Burnley it meant that the unfit Mario Jardel was the only forward cover for Henrik Pedersen and Kevin Davies.
"We asked if we could keep him here, but they [Bolton] said they need him as cover," Gradi said.
"They have loaned a couple of players to Burnley and they need him back in their squad. That is Bolton's business and that's fine. It's a shame because I went to watch him [Walters] play for our reserves in midweek at Tranmere and he did very well - he scored a good goal.
The Crewe boss also felt the youngster was an able deputy to first choice strikeforce Dean Ashton and Steve Jones.
"He looked the part, he looked as if he could come in for either Dean or Steve and done well, but now I'll have to look elsewhere."