Menseguez joined the Baggies from San Lorenzo on transfer deadline day and he will stay with Tony Mowbray's side until the end of the season.
The Argentine winger made his debut on Sunday as he came on for the final 10 minutes of the 2-0 defeat to Fulham.
Simpson has been impressed by Menseguez in training and believes his arrival should add an extra dimension to West Brom's attacking threat.
"He looks like a good player so far in training," Simpson told the Birmingham Mail.
"Hopefully he can take that into matches. It seems like he can get past defenders and put crosses in.
"Let's hope he will bring something to the team that can help us win games and keep us up."
PartnershipSimpson, who moved to The Hawthorns on loan from Arsenal in January, has linked up well with Marc-Antoine Fortune in recent weeks.
The 20-year-old is confident the partnership will develop as West Brom continue to fight for Premier League survival.
"I like working with Marc," said Simpson. "He works hard and we work well off each other, going in behind and coming to feet.
"I think the more we play together the better we will become as a partnership.
"Hopefully we will get some more goals between us.
"From the first day he came in we played well together in training and hopefully we can become a good partnership."