SANTA CLARA, Calif. – Santa Clara men's basketball has added a pair of talented transfers from power four conference programs in the form of David Castillo and Sidi Gueye. Castillo joins the Broncos by way of Kansas State while Gueye joins from the University of Arizona.

David Castillo | Guard | 6-1 | 180 | Kansas State
Castillo signed with Santa Clara after two seasons in Manhattan, Kansas, where he made 64 total appearances and 18 starts with the Wildcats. The six-foot-one guard played in all but one game as a true freshman in 2024-25 in which he averaged 2.4 points before seeing a major increase in production last season. The Bartlesville, Okla., product ranked fourth on the team in scoring at 10.3 points per game on 40 percent shooting, including a 35.2 percent clip from 3-point range. He had 13 double-figure scoring efforts with a pair of 20-point games, dropping a career-best 22 points against Bowling Green and posting 20 points on 6-of-9 3-point shooting against Utah. Castillo started 16-of-32 games as a sophomore, including the Wildcats' final 14 games of the season.

Castillo originally signed with Kansas State as a consensus four-star prospect in which he ranked as a top-15 guard nationally and was the consensus No. 1 prospect from the state of Kansas. He played his senior season in 2023-24 at prep powerhouse Sunrise Christian Academy in the Nike EBYL Scholastic League where he led the team with 13.2 points on 37 percent shooting. He led the entire league in free throw percentage (97.0) and ranked eighth in 3-pointers per game (2.4). He was also selected to the prestigious Nike Hoop Summit.

Prior to making the move to Sunrise Christian, Castillo played at Bartlesville High School in Oklahoma where he left his mark as the program's all-time leading scorer with 1,594 points – an average of 23.7 points per game over his 67-game career. He also averaged 5.6 rebounds, 3.7 assists and 1.2 steals for his career. He was twice-named All-State First Team and All-Frontier Valley Conference, and in 2022-23, he was a finalist for Tulsa World's State Player of the Year and was on the watch list for the USA Today HSSA Boys Basketball Player of the Year.

Castillo, who will join SCU as a junior, also has extensive international playing experience, winning gold medals with USA Basketball at both the 2021 FIBA Americas U16 Championship in Xalpala, Mexico, and the 2022 FIBA U17 World Cup in Malaga, Spain. At the latter, he helped lead Team USA to a 7-0 mark by averaging 10.7 points while playing alongside future NBA stars Cooper Flagg, Asa Newell and Ronald Holland. He scored 12 points in both the semifinal and championship games.

Sidi Gueye | Forward | 6-11 | 215 | Arizona
Gueye signed with the Broncos after just one season with the Arizona Wildcats in which he played sparingly in 26 games. Made the most of his opportunities with a 72.2 percent shooting clip (13-of-18) and finished the year averaging 1.3 points and 0.8 rebounds while blocking a total of eight shots. His best scoring game came against Kansas State where he finished with five points. He also contributed in the NCAA Tournament opening round win over LIU with four points and pair of blocks.

Gueye, who began playing basketball at the age of 12, is originally from Guediawaye, Senegal. He signed with Arizona State out of Spain where he began playing with Real Madrid in 2021 and made himself an enticing international prospect. He earned all-tournament team honors at the 2024-25 Adidas Next Gen U18 Euroleague finals after averaging 17.3 points, 8.7 rebounds and 1.7 blocks. The team defeated Overtime Elite and INSEP Paris before falling to eventual champion Zalgiris Kaunas despite a 19-point, 13-rebound effort from Gueye. Throughout the 2024-25 season, he made four appearances with Real Madrid's senior club in the Spanish ACB League and Euroleague just shortly after turning 17 years old.

Gueye is the second transfer from the University of Arizona to sign with the Broncos since 2023. The first, Adama-Alpha Bal, would go on to earn back-to-back First Team All-WCC honors and most recently played in eight games with the Memphis Grizzlies in which he averaged 10.4 points per outing.