| Full name: | Guglielmo Costantini |
| Position: | Half-back |
| Date of Birth: | 7 November 1934 |
| Place of Birth: | Padova, Italy |
| Date of Death: | 5 July 2016 |
| Place of Death: | Rovigo, Italy |
| Height: | |
| Weight: |
Playing career:
| Season | Team | Gpd | Gls |
| 1954-1955 | SPAL | 14 | 0 |
| 1955-1956 | SPAL | 2 | 0 |
| 1956-1957 | SPAL | 14 | 0 |
| 1957-1958 | SPAL | 30 | 0 |
| 1958-1959 | Napoli | 14 | 0 |
| 1959-1960 | Napoli | 4 | 0 |
| 1960-1961 | Napoli | 5 | 0 |
| 1961-1962 | Napoli | 1 | 0 |
| 1961-1962 | Pisa | 23 | 0 |
| 1962-1963 | |||
| 1963 | Toronto Italia |
Bio:
Known in Italy as “Nini” Costantini. Started his soccer career with Clodia Chioggia. Then progressed to SPAL and Napoli. At the end of the 1960-1961 Napoli were relegated from Serie A to Serie B.
He started the 1961-1962 season with Napoli in Serie B before being transferred Serie C club Pisa.
Before the start of the 1963 Eastern Canada Professional Soccer League season he signed for Toronto Italia. Italia won both the 1963 league championship and playoff championship.
Passed away at the age of 81 in Rovigo, Italy in 2016.