In addition to all of these clubs he has also had loan spells with Leyton Orient, Partick Thistle, Torquay United, Oldham Athletic, and Cheltenham Town over the years.

He had loan spells with Leyton Orient and Partick Thistle before moving to Wally Downes's Brentford on a free transfer in August 2002.

[4] He struggled to establish himself at Griffin Park and in August 2003 joined Southend United, initially on non-contract terms,[5] signing a permanent deal the following month.

He scored just seven times in 38 appearances and was transfer-listed in October 2005 by Torquay manager Leroy Rosenior, along with Darren Garner, Mamadou Sow, Carl Priso, Morike Sako and Nick Skinner.

[15] On 8 November 2006, he opened the scoring against Tottenham Hotspur in a League Cup tie at White Hart Lane, though Spurs went on to win the game 3–1 in extra time.

[17] He was set to move to Championship club Barnsley in the January 2007 transfer window, Vale agreeing a fee of £200,000 plus Marc Richards.

[26] On 2 July, Constantine completed a free transfer move to League One side Northampton Town after falling out of favour with Gary McAllister.

[27] After only scoring three goals for Northampton and receiving boos from the club's own fans,[28] he joined League One rivals Cheltenham Town on a one-month loan on 20 March 2009.

[33] He joined Conference Premier side York City on a contract until the end of the 2010–11 season on 3 September 2010, teaming up with his former manager at Port Vale, Martin Foyle.

[45] This was followed by a spell with fellow Isthmian League Premier Division side Tooting & Mitcham United, playing one game against Metropolitan Police on 19 November.

[45] He then signed for Boston United of the Conference North on a contract until the end of the 2011–12 season,[46] making his debut as a substitute in the side's 4–2 Boxing Day victory at home to Eastwood Town.