The FA Cup, which began in the 1871-72 season and was once the glamorous highlight of the English football calendar, has paled in recent seasons alongside the Champions League and Premier League.
The major clubs regularly field weakened teams in the early rounds and, although the final at Wembley is still one of the season's highlights, the competition has lost much of its old sparkle.
"With some rounds it may be better to look at midweek fixtures rather than weekends," Watmore told Talksport Radio.
"The third-round weekend, the first week in January, is one of those iconic weekends of the football calendar and I wouldn't want to mess with that.
"The FA Cup final on the second or third Saturday in May at three o'clock is a fantastic day so I wouldn't want to mess with that for any reason.
"But if there's a really good reason to change some of the format and to bring it back to the sort of glory that it had when you or I were growing up then why not?
"We do have to do something with the FA Cup to turn it around and make it become more relevant, particularly for the younger generation of fans."
This season the cup has produced some big shocks, with Leeds United, of the third tier, winning 1-0 at Manchester United in the third round and Reading of the Championship winning a third-round replay 2-1 at Liverpool.
