|Date of birth||4 May 1988|
|Place of birth||Padua, Italy|
|Height||1.91 m (6 ft 3 in)|
|1994–1998||U.S. Alte Ceccato|
|2006–2007||→ Pizzighettone (loan)||9||(0)|
|2008||→ Venezia (loan)||7||(0)|
|2008–2009||→ Pisa (loan)||9||(0)|
|2009–2011||→ Modena (loan)||37||(0)|
|* Senior club appearances and goals counted for the domestic league only and correct as of 13 October 2016.
After that season, Alfonso joined Chievo's Giovanissimi. He was sent on loan to Pizzighettone of Serie C1 in summer 2006. He was competing with Alex Cordaz for first choice until Cordaz ended his loan.
On 27 August 2007, he joined Internazionale on co-ownership deal, for €1.9 million, signing a five-year deal with the club. He replaced Fabián Carini, who left for Real Murcia, as fourth goalkeeper (but in UEFA Champions League the 4th keeper was Paolo Tornaghi). He took the 71 shirt, which was previously owned by Cordaz.
On 17 January 2008 Alfonso made his debut against Reggina in the Coppa Italia, in the match he was forced to make two good saves in the end Inter won 3–0, and 7–1 on aggregate.
Alfonso spent the 2008–09 season on loan to Serie B side Pisa. After Pisa's relegation to Lega Pro Prima Divisione, and ultimately its financial collapse, Internazionale secured a loan move to Modena for Alfonso for the 2009-10 Serie B season. In the next season he became the starting goalkeeper of Modena, played 31 times.
Lega Pro clubs
In late July 2013 Alfonso joined Vicenza as a trialist, which he played as one of the starting keeper in the pre-season game. On 10 August 2013 Alfonso signed a 1-year contract with Vicenza and immediately submitted to the office of Lega Pro . Alfonso immediately replaced Angelo Di Stasio as the starting keeper of Vicenza in competitive game, the second round of 2013–14 Coppa Italia. He was the first choice in the match after, against Del Piero's Sydney FC. Vicenza promoted back to Serie B in 2014 as a replacement of Siena, despite finished a losing quarter-finalist in 2014 promotion playoffs.
Alfonso had been part of every minor Italy national football teams, from the under-15 till the under-21. He took part in 2005 UEFA European Under-17 Football Championship (which he was sent off in the third match) and 2005 FIFA U-17 World Championship. He was not played in any match of 2007 UEFA European Under-19 Football Championship elite qualification and rarely selected to U-19 team.
On 5 September 2007, the round 1 of 2007–08 Four Nations Tournament, Alfonso played the whole match of Italy under-20 national team against Switzerland. Alfonso managed to hold a clean sheet, as the match ended in a goalless draw.
On 5 October 2007, Pierluigi Casiraghi called up Alfonso, along with teammate Francesco Bolzoni, to form part of the Italy national under-21 football team. The national side would be involved in the 2009 UEFA European Under-21 Football Championship qualification matches against Croatia and Greece. However, he did not play nor on the bench. That season he only managed to play the third and sixth round of the Four Nations Tournament.
He was called up to the 2008 Toulon Tournament from Italy Olympic where he played 2 games keeping one clean sheet, during the group stages, after Italy already qualified for the next round with a win. He was not selected to 2008 Olympics in August. Despite still eligible to 2009–11 season, he did not received any call-up since May 2008.
- "Italy U21 call-ups for Alfonso, Bolzoni". www.inter.it. 5 October 2007.
- "Alfonso signs for Inter". www.inter.it. 27 August 2007.
- "Alfonso joins Venezia". www.inter.it. 25 January 2008.
- "ENRICO ALFONSO È UN GIOCATORE DEL PISA" (in Italian). Pisa Calcio. 23 July 2008. Archived from the original on 24 July 2008. Retrieved 23 July 2008.
- AC Chievo-Verona s.r.l. financial report and accounts (bilancio) on 30 June 2012 (Italian)
- "Vicenza-Genoa International 7-0" (in Italian). Vicenza Calcio. 25 July 2013. Retrieved 13 August 2013.
- "Al Bassano Virtus il "I° Trofeo Città di Asiago"" (in Italian). Vicenza Calcio. 28 July 2013. Retrieved 13 August 2013.
- "Amichevole di allenamento Vicenza-Trapani 0-2" (in Italian). Vicenza Calcio. 1 August 2013. Retrieved 13 August 2013.
- "Gara di allenamento Vicenza-San Paolo Padova: 5-0" (in Italian). Vicenza Calcio. 8 August 2013. Retrieved 13 August 2013.
- "Alfonso Enrico in biancorosso" (in Italian). Vicenza Calcio. 10 August 2013. Retrieved 13 August 2013.
- "Tim Cup Varese-Vicenza 1-0: il tabellino" (in Italian). Vicenza Calcio. 11 August 2013. Retrieved 13 August 2013.
- "Amichevole Sydney F.C.-Vicenza 3-1: il tabellino" (in Italian). Vicenza Calcio. 13 August 2013. Retrieved 18 August 2013.
- Lega Pro - Il Pro Piacenza si rinforza con Alfonso Sportpiacemza.it
- "Alfonso per la porta granata" (in Italian). A.S. Cittadella. 16 July 2015. Retrieved 8 May 2016.
- "Ninety minutes with Italy U20s for Alfonso". www.inter.it. 6 September 2007.
- "Italy U20 call-ups for Alfonso, Bolzoni". www.inter.it. 3 February 2007.
- "Ventidue Azzurrini a Tolone. Il 21 esordio contro la Costa d'Avorio". FIGC (in Italian). 16 May 2008. Retrieved 21 June 2011.